All Forensics Bio

What is palynology?

"The study of dust" - pollen and spores "palyn" Greek meaning I sprinkle "ology" to study "pollen" Latin meaning dust or fine flour Pollen & spores are produced by plants for reproductive purposes

rate at which a pollen grain falls to earth, an important factor when determining dispersal area

"sinking speed" Dispersion area - Important for forensics Distribution area for lightweight pollen (such as cannibis) is much smaller and more restricted than that of heavier pollen (such as birch)

Structure of state court system:

Structure is similar to the federal system: Circuit court court of appeals Highest court (reviews selected cases from court of appeals)

What are the 3 focus areas when using the pelvis to determine gender?

Subpubic region (Scoring systemFemale/male - F/M Possibly female/male - F?/M?Feature not present/non-determinable - N/P/N/D) Greater sciatic notch (not as reliable as subpubic region) - narrow in males; wide in females Preauricular sulcus

Utilizing pubic symphysis to estimate age typically involves looking at the _ phase

Suchey-Brooks Phase Each of 6 phases correlates with a different age range

thin enough to derive its nutrients from surrounding vessels, thus no haversian system required

Trabecular bone

Bloodstain due to blood being transferred from one surface to another

Transfer

Three different types of footwear impressions/shoe prints:

Two dimensional (visible) Two dimensional print (latent) Three dimensional impression

What is Sporopollenin?

a major component of the tough outer walls of spores and pollen grains. The exine layer is often intricately sculptured in species-specific patterns

What is the y axis of an STR analysis graph?

a measure of fluorescence

minutiae point where one ridge splits into 2 and forms a fork

bifurcation (very common on fingerprints. comparisons can be made between crime scene & suspect using bifuractions)

fibrous protein which provides bone with strength & flexibility

collagen (30% of bone dry weight)

3-D impression can be highlighted by Spraying with _

colored wax spray

if a single peak occurs at each nucleotide in a chromatogram, the sequence is _ if more than one peak occurs at each nucleotide, the sequence is _

homoplasmic heteroplasmic

The Glaister Equation allows calculation of what?

hours lapsed since death Hours since death = 98.4°F - internal body temperature /1.5 Used as a starting point to determine time of death - ultimately use other factors to corroborate a more accurate time.

Invisible to naked eye, left behind when oils and perspiration are transferred from a finger to an object. Must be enhanced to make them visible.

latent prints

Other resources for searching for a burial site

law enforcement medical examiners Cadaver dogs, search and rescue teams or divers ^ cadaver dogs work best in moist environments, which makes the scent in the air more intense forensic anthropologists are generally on scene during the search process

Medical examiner will use multiple factors to calculate time of death.Always a small margin of error. If body is warm but not stiff, time since death is =

less than 3 hrs

position of a gene or section of DNA on the chromosome

locus

A dental record "match" will be ascertained under what circumstances?

no significant differences observed - any differences can be explained

The soil is usually divided how?

naturally occurring stratigraphic layers, differentiated by color texture & grain size. The deeper layers are older; this can aid in determining how long the body has been there. The soil is then filtered through a wire mesh to uncover trace evidence such as hairs or fibers, which would be collected & documented

mtDNA extraction is performed how?

same methods as nucDNA (amplified via PCR) must be in a clean environment due to high copy # reference samples taken after forensic sample for comparison mtDNA results compared to database

What makes a bone a "short" bone?

same width as their length - primary function is support/stability for movement

Like the dermestids,_beetles arrive when the body is completely dry

scarab beetles

cancer cells that move from the organ of origin to another region of the body

secondary tumor

more porous bone Honeycomb/sponge-like structure Forms interior of bones

trabecular bone

how is DNA contamination prevented?

training staff (to wear gloves, etc) restrict access keeping a DNA database of the staff who handles the DNA ensure lab is clean/sterile (autoclaves & UV-crosslinkers remove foreign DNA via extreme heat or UV light) use plastic/disposable equipment switching pipette tips for each sample aliquot reagents (using small amounts & disposing of it once finished) running positive (sthg we know contains DNA) & negative controls (sthg that does not contain DNA)

Created when a wet, bloody surface comes in contact with a secondary surface

transfer bloodstain (contact bleeding, swipes, smudges, smears)

In contact with paint, blood, grease, ink, chalk dust etc. Visible ridges

visible prints

If 2 female blood samples were mixed together, & you amplified the amelogenin gene, & ran the DNA on an agarose gel, how many bands/fragments of DNA would you expect to see?

1

chance that 2 unrelated individuals selected at random would have the same STR profile (match probability) = what?

1 / genotype frequency

4 stages of fracture repair

1) hematoma formation (10 days) 2) callus formation (12-15 days) 3) callus ossification (6 wks) 4) bone remodeling (months-yrs) We can use fracture repair to date when an injury may have occurred which can help ID skeletal remains

steps in DNA sample processing

1) identify organism from which it came 2) prepare controls 3) extraction: isolates DNA from the cell

DNA analysis steps

1)collection of DNA evidence from scene 2)extract DNA from sample 3)amplify region that must be examined 4)create DNA profile 5)interpretDNA profile

how is gun evidence recorded?

A gun may be used for ballistic analysis of bullets fired, fingerprints on gun, find out if it was recently fired, comparison of bullets at crime scene vs those in gun

How can DNA and transplants cause potential misidentification when drawing blood to create a DNA profile?

A man donated bone marrow to his brother, thus his stem cells generated new cells within the brother. As a result, when the blood was taken from the brother, the DNA matched the person who had donated the blood rather than the person who had received the transplant. Buccal swabs are exempt from this potential error, as transplants cannot affect saliva. Thus both swabs and blood should be used when generating a DNA profile.

In what cases has chDNA aided an investigation?

A study was conducted using the chDNA of C. sativa, the results of which can be used to identify the presence of cannabis on the skin of individuals - indicative of recent handling the illegal plant. In this case the RAPD-PCR technique was not used; instead a universal primer was used to amplify the chDNA of C. sativa. Once the amplified DNA was sequenced, a specific fragment was identified as specific to the C. sativa plant strain. Thus the primers used in this study can be used to confirm the origin of seeds or plant material.

The following cranial features are evident in which ethnicity? Ovoid vault Sloping orbits Nasal aperture:Narrow, Inferior border sharp No prognathism (over/underbite)

European

To determine ethnicity, what are the 3 major groups and what 2 features are looked at?

European ancestry,African ancestry,Asian ancestry Main focus is the cranium and mandible

Why are teeth forensically pertinent?

Every human body ages in a similar manner, the teeth also follow a semi-standardized pattern. These quantitative measurements help establish relative age of person. Each human has an individual set of teeth which can be traced back to established dental records to find missing individuals. Teeth is made of enamel (hardest tissue of the body) so it can withstand trauma (decomposition, heat degradation, water immersion, and desiccation) better than other tissues in body. Teeth are a source of DNA: dental pulp or a crushed tooth can provide nuclear or mitochondrial DNA that to help identify a person.

How can a case go from a state to federal court?

Ex: Miranda was tried in a state court for a crime. They felt that his constitutional rights were infringed upon due to not fully understanding his rights when arrested. They appealed to Arizona supreme court, and eventually to the federal supreme court.

A Reasonably accurate method of child age determination is examining epiphyseal unions. What is the method for this?

Examine bones to identify the degree of fusion between the epiphyses and metaphyses

Late-arriving species, tend to be specialist scavengers which feed on tougher parts like skin and tendons as the body dries out.

Hide Beetles (Toridae) Family name: Dermistidae

among the first beetles to arrive after carrion. They generally hide under a corpse during the daylight, and only become active at night when they enter the maggot-infested part of the corpse to capture and devour maggots.

Hister beetles The adults feed on both the larvae and pupae of all species of blowfly. The adults lay their eggs in the corpse, and the larvae feed on blowfly pupae when they emerge.

What are fingerprints used for?

Not only for criminals, but also to track people (such as in airports, particularly immigration).

Hardy Weinberg principle formula

(p+q)^2 = p^2 + 2pq + q^2 homozygous allele = p2 (allele frequency squared) heterozygous allele = 2pq p & q are the alleles

alternative methods used to determine whether we have animal or human remains

*Bone macrostructure* (overall structure) Animal bone have a greater density relative to the size Cortical bone - less or more porous Thickness of diameter of the long bone *Bone microstructure* (microscopic) Osteons or aversion system (functional units within compact bone) present in most mammals, & some birds amphibians & reptiles. The size & shape can tell us whether we have human or animal remains Osteons in human bone are evenly spaced Osteons in animals tend to align in rows and may be scattered into bands (the banding pattern is looked at)

Long bones are composed of what 3 regions?

*Diaphysis* (shaft) Thick cortical bone wall Hollow medullary cavity *Metaphysis* (flared ends) Thin cortical bone wall Filled with trabecular bone *Epiphysis* (sites of articulation) Thin cortical bone wall Filled with trabecular bone

Examination of human remains by forensic anthropologists focuses on what three tasks?

*Identifying the victim* or at least providing a biological profile ( age, sex, stature, ancestry, anomalies, pathology and individual features). *Reconstructing postmortem period* based on condition of the remains and recovery context. Providing *data regarding death event*, including evidence of trauma.

What are the issues/problems with LCN PCR?

*Increased sensitivity increases the risk of contamination* LCN produces mixed profiles and partial profiles LCN requires rigour in the lab in order to avoid contamination Care needs to be taken at the crime scene when collecting evidence Transfer of DNA through innocent contact - hand shake This transfer of material can be demonstrated in laboratory experiments

skeletal changes associated with epigenetics

*Ossification of the pterygoalar ligament/bar* (bony ridge within skull that forms as a result of an epigenetic change - fairly rare, thus useful in ID) *Malocclusion of the teeth* (additional teeth present in jaw or not enough space in jaw for teeth to be there - this person would have likely have gone to the dentist & dental records can be used for ID) *Supra-orbital foramen* (small opening superior to each eye socket which carry supraorbital vessels & nerves from orbit to anterior surface of bone)

What are the main functions of bone?

*Protection* (for internal organs and fragile body tissues) *Support* (bones must be strong, light & aid in muscle attachment) *Mineral storage* (solid mineral crystals found in bone which allows us to withstand physical stresses - calcium, phosphorous, magnesium, fluoride. Bone can release calcium & magnesium into bloodstream as needed) *Red blood cell formation* (within bone marrow, blood cells will differentiate into different lineages including red blood cells)

The mitochondrium may contain _ to _copies of the mitochondrial genome, tho it varies The cell contains how many copies of the nuclear DNA chromosomes?

10 to 100 (or thousands if it's a muscle cell) only 1 ^this is why mtDNA is so useful, especially within a degraded organism which may have all its nuclear DNA degraded.

Forensic scientists in USA have standardized _ STRs for entry into a national database known as the Combined DNA Index System

13

What was the progression of fingerprint history?

1686: Marcello Malpighi, first to notice *patterns of skin on fingers is distinct* 1823: *Whorls, ellipses, and triangles* identified by Jan Evangelista Purkinjie 1858: Sir William Herschel, *used fingerprints on contracts in India* - may have known of the individual identification associated with fingerprints 1880: Fingerprints used by Henry Fauld to *identify criminals* 1892: Galton developed the *classification of fingerprints*

Fingerprinting history continued

1896: System of matching fingerprints to identify people developed by Edward Henry 1900: Scotland Yard adopts the Henry system of fingerprinting 1902: First person was convicted on fingerprint evidence 2013: The Integrated Automated Fingerprint Identification System (IAFIS), is the USA national fingerprint and criminal history system

Forensic palynology: term introduced in _

1982 First case in 1959, in Sweden. A woman killed in May during a trip to central Sweden. It is unknown if this case was ever solved.

How is DNA collected in the UK?

2 buccal swabs at time of arrest 10 hairs pulled from root blood sample

stature calculation based upon femur length

2.32(femur length)+65.53

National DNA database in the UK was introduced in _ and operational in _ Their database is made up of what 2 components?

2009 - 2010 5 matches were made in the first yr suspect database & crime scene database

Humans have _ pairs of chromosomes (autosomes & sex chromosomes)

23 For each pair of chromosomes, one chromosome comes from the father & one comes from the mother.

When will beetles only be found on a corpse?

3+ yrs

If body is warm & stiff, time since death =

3-8 hrs

Approximately_teeth in adult mouth

32

***She will ask which # was given during the lecture****

5892

When will mites be found on a corpse?

6-12 mos, between ammonia fermentation and corpse being completely dry

History of forensic odontology

66AD - First body identified using teeth Lollia Paulina Revolutionary War Paul Revere was the first forensic dentist in the United States because he identified fallen revolutionary soldiers. 1849 - Dental evidence is first admitted into court system in US Webster-Parkman case Dr. Webster found guilty due to the finding of a tooth with gold which belongs to Dr. Parkman

If body is cold & stiff, time since death =

8-36 hrs

What are some potential errors in DNA profiling?

9 matches out of 13 STRs is not enough to equate to a "unique" profile; many profiles have been found to match 9 out of 13, yet many experts have said that 9 matches is tantamount to a unique profile. This could lead to wrongful convictions, and also poses an issue for the UK database, which only examines 10 STRs

Why is Y DNA analysis useful?

98% of violent crimes are committed by males Autosomal testing is difficult when there is a mix of female victim's blood and male suspect's blood. In this case, any Y chromosomes found must belong to the male suspect. This makes it easier to separate the Y from the other autosomal chromosomes which might be present - no need for extensive extraction techniques. Also can be used to determine male lineage - useful in immigration or in establishing if a # of people within the same family are involved in a crime

If body is cold & not stiff, time since death =

>36hrs

Metabolic diseases can result in what?

A change in the balance of osteoblasts (build bone) and osteoclasts (break down bone), which can result in remodeling of the bone. Ex: Osteoporosis Diffuse Idiopathic Skeletal Hyperostosis (DISH)

Define the term universal database & explain one benefit & 1 reason against trying to implement it

A universal database would be a collection of DNA profiles from all people, worldwide. DNA would be taken from people at birth and the profiles generated from the samples would be stored on the database. One benefit would be that it would remove the stigma associated with having your profile on the database. A potential drawback is that it would be a costly endeavor when most people do not commit crimes & DNA is not relevant to every kind of crime (i.e online crime).

LCN PCR is now routinely used why & for what?

Able to produce a DNA profile from a single cell Profile skin cells from a fingerprint Profile a single hair Used when there is insufficient DNA to run a standard profile Old stored evidence from unsolved cases Evidence which previously failed to provide a profile

Wear on the teeth associated with Objects held in teeth E.g. pipe smoking

Abrasion

Body is discovered at 11am on June 23rd and insect samples are collected at noon the same day. The most mature developing insect is the Calliphora vicinia larvae, found on the body which is molting from the second instar to the third instar. When did the Calliphora vicinia female lay these eggs?

Accumulated degree hours (ADH) Calliphora vicina Developmental stages Egg stage - first instar 14.4 hours First instar - second instar 9.6 hours Second instar - third instar 24 hours Third instar - adult 158.4 hours

Bloodstain which is due to a force other than gravity

Active

How to perform a presumptive field test

Add suspected substance to the pouch. Seal Break ampoules in order Check for color change Still need to be careful of false positives

Another condition in which normal decomp process does not occur Favored by damp conditions Wet soil Submerged conditions Process takes years to complete

Adipocere formation Gray, waxy appearance which forms from hydrolysis of body fat Body may be buried in wet soil or submerged. Formation of adipocere maintains integrity of contours of body

At the decay stage of decomposition, what insect activity is there?

Adult blowflies no longer attracted. Large masses of maggots feeding externally and internally Predators and parasitoids of maggots arrive

Structures of justice systems

Adversarial:legal system where two advocates represent their parties' positions before an impartial person or group of people, usually a jury or judge, who attempt to determine the truth of the case. The US uses this system Inquisitorial: the court or a part of the court is actively involved in investigating the facts of the case. France uses this system.

methods of archaeological recovery

Aerial or infrared photography - allow experts to search photos for signs of burials or areas of interest. 3D photographs and the use of filters can enhance the photos to allow discernment of terrain & plants, which can aid in finding burial site. Thermal imaging Ground penetrating radar Metal detectors

How is temp taken into account when estimating PMI?

Affects decomposition rate Affects insect variety and abundance (Colder temperatures result in decreased growth)

How is exposure taken into account when estimating PMI?

Affects diversity and abundance Buried bodies decompose slower and are less accessible to insects than exposed bodies Scavenging animals

The following cranial features are evident in which ethnicity? Flat vault Square orbits Nasal aperture: Wide Inferior border guttered Prognathism

African

What are the "big four" that form the basis for identification from skeletal remains?

Age, gender, ethnicity, stature Important to form conclusions on as much material as possible Useful in narrowing down police searches Need to highlight individualising features to form identification

What is involved with determining temp history at crime scene (step 2 of determining PMI)?

Air temperature for general area (airport readings, validate with micro data-loggers). Look for 'windows' of insect opportunity

What is the process of mass identification?

All completed cases put before an identification committee. Once identification has been made the remains can be released to the family. It can take time to make the final identification: Collecting the remains Collecting the antemortem information Delays due to time taken to perform forensic analysis Important to have good communication with the families and to keep them informed of progress.

How is footwear evidence recovered?

All shoeprints should be recovered from the scene. (brand of shoe, etc is important bc we can look at how rare the shoes are) Scene should be controlled to prevent destruction of evidence. Some prints can be visualised by darkening a room and using a bright light at a low angle. Shoeprints should be documented: Location recorded and photographed. Objects with shoeprints should be removed if possible (glass) If can't be removed, an *examination quality* photograph should be taken. Ruler: allows for enlargement to real size

The "dark reaction" refers to what?

Also called the Calvin Cycle, it is the part of photosynthesis in which carbon dioxide is fixed using energy in the form of ATP and NADPH. The cycle spends ATP as an energy source and consumes NADPH2 as reducing power for adding high energy electrons to make the sugar. There are three phases of the cycle.

What forensic flaws exist?

Although DNA is hailed as the 'gold standard' of identification techniques, the more humble fingerprint retains its status as the most commonly used method of identification and is a cornerstone of forensic crime scene investigation. Despite controversy over the standard required before a 'match' can be declared, fingerprint evidence generally remains unassailable in the criminal courts as a unique identifier. However, disputes can and do arise about methods of collection or negligent interpretation, and there have been several criminal cases where fingerprint evidence has proven flawed.

What is forensic entomology?

Application of insects to legal issues - Medicocriminal forensic entomology.

In STR profiling, which locus is used to identify if the individual is male or female?

Amelogenin

Progressive inflammatory disease Later ossification of tendons and ligaments Primarily affecting: Diarthrodial joints of the spine Costovertebral joints Sacroiliac joints

Ankylosing spondylitis Disease begins in lower lumbar vertebrae or sacroiliac joint Progresses up the spine Results in fusion of vertebrae/ribs or 'Bamboo spine' (end result of fusion resembles bamboo)

What Results in fusion of vertebrae/ribs, or 'Bamboo spine'?

Ankylosing spondylitis, thought to mostly affect people between ages of 17 & 45

What are the roles of the antemortem and postmortem teams in the case of a mass disaster?

Antemortem team - collect dental records from families Postmortem team - examine the remains and examine the identifying features Compare the results to determine if an identification is possible.

What are the 4 methods for pollen dispersal?

Aquatic transport Self-pollination Zoogamous transport (animal transport) Wind pollination Pollen sinking speed in air also important - will help determine how far the pollen will be able to travel..

The following cranial features are evident in which ethnicity? Arched vault Rounded orbits Nasal aperture: Medium, Inferior border dull Slight prognathism

Asian

Anthropologists play a key role in developing the profile. This includes:

Assessing skeleton for shape and sex, which allow estimate of age, sex and ancestry. Stature of victim Unique healed bone figures or distortions, and dental configurations assist in constructing profile.

Wear on the teeth associated with age & diet

Attrition

Wear on the teeth can indicate certain aspects of lifestyle

Attrition (associated with age & diet) Abrasion(Objects held in teeth E.g. pipe smoking) Erosion (Acidic wear, such as that resulting from Vomiting or disease)

Area where the ilium articulates with the sacrum How does this change with age?

Auricular area Morphological changes with age include billowing, granulation, porosity, transverse organization & increased finesse

What are the features of computer odontology?

Automatic dental code matching Bites are run through the computer to find a match OdontoSearch Compare a data base of missing peoples, felons, government workers Automatic dental identification system A few minutes will produce a list of people who have the same dental code number 3D Bite mark analysis 3D scans of dental casts are used to generate overlays using various pressure and deviation. The overlays are compared with the photograph of the bite marks.

Why wouldn't the chloroplast be considered self-sufficient?

Because its genome does not contain all the necessary genes to code for the polypeptides of ATPase, which is required to generate energy in the form of adenosine triphosphate (ATP) which is critical for photosynthesis

Why is only region within each chromosome analyzed in STR analysis?

Because the chromosome is inherited as a whole unit, looking at more than 1 region per chromosome would be redundant

At the scene of a crime, the evidence collector found a damp bloody shirt. He quickly wraps the shirt in a paper bag. He inserted the bag into an evidence bag, sealed it with tape & wrote his name across the tape. The evidence collection log was completed and taped to the bag. What did he do incorrectly?

Because the shirt had blood on it, it should have been photographed prior to packaging. A clear picture of the blood spatter may aid the blood spatter analyst's interpretation. Because the shirt was damp, it should not be stored in a paper bag. This could promote mold growth which could damage the evidence. Instead it should have first been dried or stored in a plastic bag in a freezer or refrigerator to prevent mold growth.

How are bite marks analyzed?

Bite marks are photographed with a scale(Bite marks on skin are taken over repeated intervals) Casts of impression are taken Impression traced onto transparencies Casts of suspects teeth are taken Comparison between suspect cast and bite mark

stage of decomp in which Flesh of creamy consistency, with exposed body parts black. Body collapses as gases escape. Fluids drain. Odor of decay very strong (10-20 days).

Black putrefaction likely to see a large maggot mass, leading to a considerable increase in odor

Locard's exchange principle implies all of the following EXCEPT: Soil samples can be carried from the yard into your home. Fibers can be transferred from one person to another. Cat hair can be transferred to your pants. Blood spatter can be used to identify blood type.

Blood spatter can be used to identify blood type. ^This answer is not related to Locard's exchange principle. It states that every contact leaves a trace.

are attracted to dead bodies and often arrive within minutes of the death of an animal. They have a complete life cycle that consists of egg, larva, pupa, and adult stages.

Blow flies

often are an attractive blue-green, metallic color, leading to the common English names, blue-bottles and green-bottles.

Blowflies Blowflies can pick up faint traces of the odor of decay from up to 20 km away and lay their eggs in a suitable corpse.

Describe the blowfly life cycle

Blowflies are attracted to the odor produced by a decaying corpse, which draws them to their body to lay their eggs and subsequently produce maggots. Once the adult flies lay their eggs, the eggs develop into pupae (maggots) in 12- 24 hours. The maggots pass through 3 instar stages, develop into pupae and emerge as adult flies in 6-8 days.

At the fresh stage of decomposition, what insect activity is there?

Blowflies have detected the cadaver Eggs are being laid, often around the eye, nostrils, mouth, followed by anus or genital openings

How is location taken into account when estimating PMI?

Bodies in dry environments will decompose before insects can properly colonize Bodies in wet places will attract a different set of insects

What is involved in the arraignment process?

Bringing the arrested suspect before a judge, naming the charges, and allowing the person to enter a plea (guilty, not guilty, etc)

Consists of a hard bony growth growing on another piece of bone Not more than 2cm in diameter Commonly found on outer surface of cranial vault Usually frontal and parietal

Button osteoma - may be related to embryology, an injury, or infection

stage of decomp in which Cadaver drying out. Some flesh remains at first; cheesy odor from butyric acid (20-50 days).

Butyric fermentation

The DNA Identification Act of 1994 formally authorized the FBI to operate _ & set national standards for forensic DNA testing. CODIS became operational in _

CODIS 1998

USA database is called _

CODIS (combined DNA index system) NDIS (national DNA index system) *refer to both as CODIS for this class

At the bloated stage of decomposition, what insect activity is there?

Cadaver begins to swell and putrefy Blowflies are still ovipositing Flesh flies appear Small maggots are feeding

At the post-decay stage of decomposition, what insect activity is there?

Cadaver is drying out. Large maggots are leaving or have left

Scanning electron microscopy allows magnification up to _ times

Can magnify specimens up to 2 million times This gives us a detailed picture of the sporopollinen, as well as the networked structure which holds the pollen and gives it its resistant characteristics. The protective function of the sporopollinen is what allows us to view the pollen many yrs later (even that which is millions of yrs old)

How can pollen evidence be relevant to crimes involving illegal drugs?

Cannabis: Growing, harvesting, and packaging cannabis often occur in the open = pollen Turning cocoa leaves into cocaine begins with the leaves being picked and dried in the open, and then refined into cocaine = pollen To produce heroin the outer surface of a poppy's immature seed pod is scarred = pollen from local trees can stick to the sap

What are the steps of the Calvin Cycle?

Carbon fixation Reduction Regeneration Energy to fuel chemical reactions in this sugar-generating process is provided by ATP and NADPH, chemical compounds which contain the energy plants have captured from sunlight.

among the last beetles to inhabit a carcass. They feed on dried remains such as skin and ligaments.

Carcass beetles Both adults and larvae feed on the carcass and the larvae live in vertical burrows underneath it when they are not foraging.

What type of cases are tried before the federal courts?

Cases involving constitutionality of the law Cases involving US laws & treaties Disputes between 2 or more states

are attracted to the cheesy odor which emanates from a corpse during the later stages of decomposition, particularly when the body is undergoing butyric fermentation.

Cheese flies They are also common pests of cheeses and hams.

What is the procedure for collecting pollen/spore samples?

Chemically process evidence & samples-including control samples from crime scene. If mud samples are being obtained from a car, the control sample would be a swab of the car that does not contain mud, but does contain the same paint (possibly just a few centimeters higher than the samples). Microscopic or DNA analysis may be performed, as well as examination of dispersal patterns. Results should be compared to sample evidence

animal activity may change part of the corpse; how?

Chewing - can resemble trauma may remove body parts from decaying corpses

evidence that requires investigator to infer certain facts.

Circumstantial evidence

can be used to eliminate a suspected shoe or suggest a shoe could have made the impression. examples are size & pattern

Class Characteristics (such as size or pattern)

As a police officer you stop & search a suspect. You find white powder on them so you decide to perform a field test for cocaine. Describe the steps you would take when performing the test.

Collect a sample of the powder. Perform presumptive test at the scene. If this results in appropriate color change reaction, take the powder back to the lab for confirmation testing.

Adults are most common at corpses in the early stages of decomposition when the corpse is moist.

Common House Flies Family name: Muscidae

Disorders that are present at birth and/or form through development

Congenital & developmental disorders Ex: Developmental dysplasia of the hip (DDH) Previously known as congenital dislocation of the hip (CDH) Causes -Abnormal acetabulum (hip socket) formation & Unstable hip joint which may be inherited or developed during foetal life There may be medical records associated with it

Dietary deficiency markers include what?

Cribra orbitalia - pores in superior region of orbits Porotic hyperostosis - external superior aspect of skull vault Indicative of iron deficiency anaemia Both conditions are similar Spongy or netted appearance

Correct collection of evidence requires what?

Documenting the location where the evidence was found Correct packaging of evidence Maintaining proper chain of custody

How is a database utilized when there is no known suspect?

Crime scene DNA is compared to profiles in national DNA databases

What is involved with collecting samples of insects present (step 1 of determining PMI)?

Critical to collect the largest maggots on the cadaver, even if they are few. Representative samples of other maggots present. Preserve some immediately. Rear others to adulthood to confirm species ID's

Why is alcohol used for alcohol precipitation of DNA during extraction?

DNA does not dissolve in alcohol - rather, it precipitates out of the solution. it appears as long white strands.

process by which DNA is separated from biological material (blood, saliva, hair, teeth or bone)

DNA extraction - type of extraction depends on amount of DNA sample & type of biological material we are separating it from

DNA extraction method most applicable for forensic analysis - & most frequently used for this

DNA extraction kits silica spin column most often used solutions are specific to the manufacturer

How else is a body identified using DNA?

DNA from body can be compared to profiles on missing person's DNA database *DNA can be collected from blood, buccal swab ,tissue specimen, previously performed biopsy samples, teeth (baby teeth or adult), contact lenses, hair/tooth brush

What are "DNA misses"?

DNA matches which are nearly a match to the profile but are not exact - this is where familial searching may come into play, as the DNA miss may have been close to matching the profile because the person is related to the suspect

Information stored on UK DNA database

DNA profile unique reference # arrest summons w/ # on it which links it to PHOENIX subject's full name, age, DOB, ethnicity police force & station reference code officer who collected sample

what is on the crime scene database?

DNA samples obtained from crime scenes, including samples obtained from victims

Mixed DNA profiles are a major problem for DNA analysis. This is when samples from 2 different people are present, making it impossible to tell which alleles belong to which person. What technology has been developed to combat this?

DNAboost - software which can separate mixed profiles It could increase detection rates by 15% Could increase chances of getting a profile by 40% May supply many new leads for cold cases Can identify multiple users of a weapon, or multiple participants in an attack if blood is left at the scene There is concern that use of this could lead to miscarriage of justice, as it has not undergone a lot of independent testing

Once in the thermocycler, what is the next step of PCR reaction?

Denaturation (causes hydrogens bonds to separate in order to create ss DNA) Primers are then able to bind to sections of DNA where there are complementary nucleotides Temperature is then reduced in order to allow hydrogen bonds to reform, allowing nucleotides to add to region of interest Temp is increased again & taq enzyme speeds up synthesis

What info is collected in postmortem examination & used to determine a match?

Dental arch shape Number and position of missing teeth Size, shape & material of restorations (fillings) Individual tooth characteristics: size, shape, color, damage

Disease caused by lytic activity of bacteria on teeth For example lactobacilli and streptococci

Dental caries Occurs in acidic environment (Neglect or Refined carbohydrates) Affects the enamel, dentine and root of a tooth - creates cavity

Assessment of dental disease can indicate lifestyle, such as:

Dental enamel hypoplasia Dental attrition, abrasion and erosion Dental caries

Horizontal grooves seen on teeth Suggest periods of famine Results in teeth having less than normal amounts of enamel

Dental enamel hypoplasia In children can be seen when being weaned of mothers milk Doses of tetracyclines may produce beige bands across the teeth similar to DEH

How do you know whether a loop is a radial or ulnar loop?

Depending on which direction the opening of the loop is pointed towards. If opening toward the thumb, it is radial. If opening toward the little finger, it is ulnar

Autopsies occur in forensic and non-forensic cases & have several goals:

Determine the identify of the decedent Determine the cause of death Determine the manner of death Determine the mechanism of death Determine the time of death

Though dental records are important (Written notes,Charts and diagrams,Medical and dental histories,X-rays,Photographs,Models & Results of tests), the limitations include:

Different chart systems Different terminology Inaccuracies Illegible Poor quality results Lost or damaged files

What are the methods used for estimating age using an adult skeleton?

Differing methods: Pubic symphysis Sternal rib ends Auricular area Cranial suture fusion Age-dependent pathologies

Characterised by excessive new bone growth Increased osteoblastic activity - opposite of osteoporosis, considered a form of arthritis

Diffuse Idiopathic Skeletal Hyperostosis (DISH) Main areas seen:Along right side of spine, Ossification of ligaments/ tendons results in fusion of bones, Ossified ligaments fuse spine together Cause is not known; Believed to be related to lifestyle Possibly high protein diets

_ is the process by which a picture is converted into a digital computer file. An important and useful tool, especially for fingerprint identification, is the_that places two images side by side and allows the examiner to chart the common features on both images simultaneously.

Digital imaging - With the help of digital imaging software, fingerprints, which are often not in perfect condition, can now be enhanced for the most accurate and comprehensive analysis. (useful but can't be submitted to court) Photographs of fingerprints are often taken before they are dusted for. compare function

Computer database Capable of matching antemortem and postmortem results for mass identification

Disaster Victim International System Final match confirmation is made by the forensic odontologist, not the computer program

Physical characteristics of bite marks which are noted by the forensic odontologist

Distance from cuspid to cuspid Tooth alignment Teeth width, thickness, spacing Missing teeth Wear patterns including chips and grinding Dental history including fillings, crowns, etc.

Limitations of using ADH

Does not calculate a separate ADH for each hours of the day Assumes the relationship between the developmental rate and temperature is linear There is a big difference between the temperature in which the insects developed in the lab, vs. the temperature at the crime scene Caution must be taken when interpreting these results

stage of decomp Cadaver almost dry; slow rate of decay. May mummify (50-365 days).

Dry decay (diagenesis) This can occur much more quickly in very warm climates, and vice versa. Cracks in bones at this stage are natural part of decomp, not due to injuries occurring prior to death

Why might profiles be similar?

Duplicate profiles on database incorrect allele frequencies (certain STRs might be inherited as a group rather than individually - this would increase the # of STRs which match between unrelated people) large #s of relatives on database human error

Different Y STR profiling kits are available for forensic use. How do they differ?

Each examines a different number of loci within the Y chromosome. The basic kit examines 9 loci which are standard for Y STR analysis (minimal haplotype). Other kits examine additional loci. The more STR regions you look at, the more likely you will see diversity within your population.

Method involving assessing the degree of suture closure at specific landmark points

Each scored 0-3 0 - Open, no visible closure 1 - Minimal closure 2 - Significant closure 3 - Complete obliteration

After photo, 2-D print can be lifted via which methods?

Electrostatic Lifting:A charge is used to lift dry materials from surface to black film.The background can provide more contrast.Photographed for evidence Dusting:Fingerprint powder can visualise print

occurs when mineral salts calcify along the scaffold of the cartilage in the fetus, beginning at around 5 wks after conception (calcification)

Endochondral ossification

Before beginning an excavation, what must be done?

Entire area must be photographed Perimeter established Area must be gridded to complete spatial measurements (grid search because it's likely to be an expansive area with multiple searchers participating) Flags or stakes can be used to note "hits" for evidence related to burial siteMetal detector may be used and "hits" flagged Examination for insects, larval or adult, should be collected and preserved. Postmortem plants associated with body should be collected. It's important to collect as much evidence as possible, as it might not be possible to go back later for evidence especially if the burial is outside (which it typically is)

Main areas of individualizing features

Epigenetic traits Congenital and developmental disorders Metabolic disease Joint disease Dental disease Infections Dietary deficiency markers Neoplasia (abnormal growth) Ante-mortem trauma ^these can be compared to medical records or discussed with family & friends

Heritable change in gene function without change in DNA sequence

Epigenetic traits May be induced spontaneously in response to environmental factors Example: methylation, when a methyl group can be added or removed to DNA nucleotides without affecting the nucleotides themselves- this can occur within the gene promoter region. if it does, it can turn the gene on or off. Epigenetic modifications can result in changes in bone structure

What does it mean that epigenetic traits can be non pathological?

Epigenetic traits may not cause a pathological change or change in bone, thus it may not cause pain or be reported & subsequently recorded in medical records. They may not be the best thing to look for identifying remains for this reason

How is forensic entomology used in death investigations?

Establishing timelines (time since death to time of discovery - postmortem interval or PMI) Movement of the corpse, manner and cause of death. Association of suspects with the death scene Detection of toxins or drugs -> insect larvae

_of body or skeleton prior to removal from gravesite assists in investigation. Grave perimeter should be closely inspected for_ Body or skeleton removed to body bag. - or individual bones will be packaged & labelled

Exposure footprints, tools - footprints can show if the body was carried or drags - tool marks can show us how the burial site was dug

If there is an elevated ridge present in the ventral arc, is it M or F?

F

If the pubic arch is broad, is it M or F?

F - it is narrow in males

T or F The very first walk thru of a crime scene by a first attending officer involves a search to locate possible items of evidence.

FALSE The initial walk thru is to establish health & safety, to determine if the scene is safe to enter & see if there is anyone present on the scene who needs medical assistance

If we have a skull, another way we can ID the victim is _

Facial (2D or 3D) reconstruction is another identification aspect - may be done via sketch or clay sculpture over the skull Can be subjective; still under debate but can be useful if other ID attempts have failed

What is involved in aquatic transport?

Fairly uncommon, usually occurs when pollen is distributed by flow of water in rivers & streams. This can occur by distribution on the surface or beneath the surface of the water. Surface pollination is rare, transition between wind pollination and true aquatic transport, where the pollen is completely submerged.

Types of justice systems in the US

Federal (laws which cover the whole country, Consitutional/Federal law) Local (laws dictated on a state by state basis, family law, juvenile, criminal, traffic cases)

How are the terms of federal & state judges different?

Federal judges hold office for life but can be removed or impeached for misbehavior. State judges are elected and will either serve a set term or serve for life, depending on the state.

How do you identify what kind of whorl is in a fingerprint?

First identify the 2 deltas Draw a line between the 2 deltas Draw a line around the outermost ridge which forms a complete circle See whether or not the imaginary line intersects the line drawn around the ridge. If the line intersects, it is a plain whorl. If the line does not intersect, it is a central pocket whorl.

What differentiates the male gonial flaring from the female's?

Flares outwards in males No flaring in females

Major groups of insects associated with cadavers

Flies Blowflies Flesh Flies House Flies Cheese Skippers Beetles Carrion Beetles Dermestids Scarab Beetles

What is the difference between autosomal STR profiling & Y STR profiling?

For autosomal STR profiling, we are looking at 2 chromosomes per STR region. Thus, 2 numbers will be generated for each STR site. In Y STR profiling, we are looking at a single chromosome & will generate only 1 number for each site examined

recovery of scattered remains.

Forensic archaeology

Do forensic scientists appear in court?

Forensic scientists do not have to appear in court - though they may be asked to come in to answer questions on a case by case basis The forensic report should stand alone and not require further explanation Report is aimed at non-scientist readers Results and interpretations should be frank and fair The format of the report is dictated by the nature of the investigation

interpretation of primarily outdoor death scenes and postmortem processes

Forensic taphonomy

Focus of forensic anthropology has expanded to include:

Forensic taphonomy- interpretation of primarily outdoor death scenes and postmortem processes Forensic archaeology - recovery of scattered remains. Extrapolation of soft tissue based on skeletal form Biomechanical interpretation of sharp and blunt force injuries, primarily to bone.

What areas of science is palynology useful in?

Forensics - to determine the whereabouts of an individual, examine pollen clinging to clothes Geology - we can study pollen to determine if certain sites are conducive to petroleum Archeology - studying ancient pollen samples, archeologists can determine agricultural practices, diet, etc. Anthropology - the social aspects of pollen, such as that ancient tribes used for burial of the dead Aerobiology - to determine what plants cause hay fever and allergic reactions - in landscaping

In looking at fusion of immature bones to determine age, how is the occipital assessed? What changes can be expected to emerge with age?

Forms from 4 centers:Squamous part, 2 lateral parts & a basilar part Lateral parts first fuse to squama ~1-4 years Basilar part then fuses to laterals 2-8 years

credited for first fingerprint from a crime scene (a greasy fingerprint left on an alcohol bottle)

Francis Galton

For STR profiles, what must be determined?

Frequency of alleles within population Frequency of full STR profile within population

A. _ (Days 1-2) Commences at death, ends when bloating is first evident. Breakdown of protein and carbohydrates into simpler compounds B. _ (Day 2-6) Putrefaction begins. Gasses produced by anaerobic bacteria inflate the abdomen. C. _ (Days 5-11) Abdominal wall breaks allowing gasses to escape. Carcass deflates. D. _ (Days 10-25) This stage is dependent on the temperature. There is little body mass left and the soil surrounding the remains will be stained (from body fluids). E. _ (Days 25+) Mainly bones and hair remain. Odor is primarily that of normal soil and litter. Can last several months to years.

Fresh stage Bloated stage Active decay stage Advanced decay stage Dry stage

First step in examination of human remains is to perform a taphonomic assessment. This includes what?

Full inventory of the remains (establish which bones are present/absent by laying out the bones to try to complete the skeleton) Evaluation of condition of remains (were they stripped bare during decomp? how long have they been buried? is there any soft tissue remaining?) Estimation of time since death

Environmental factors

General environment:Land slip displacing burials/Weathering of exposed bone Burial environment: Preservation of bone dependent on type of soil (Soil pH & Water movement)

Rate of decomposition can be affected by what factors?

Geographic location Time of year Sunlight (UV light can warm the body & encourage bacterial growth) If temp is too high or climate is too dry, it can inhibit decomp. Temperature must be in exactly the right range to speed up decomp. If temp is too low, it will restrict the activity of the microbes and insects

What is involved with estimating time of egg laying (step 3 of determining PMI)?

Given the species present and their age (size), how long did it take them to develop to that point at the temperatures occurring in the area.

If there is a match between pollen on suspect and a specific area, what are the next steps?

Go to the scene & see if there is evidence of a fresh burial. If there is, we can excavate the area to try to find the body.

a sound pulse is emitted into the ground & this is reflected back to a receiving antennae. The time it takes for the pulse to return can tell us the depth of the buried object, as well as its size & shape

Ground penetrating radar - limitation is it's very expensive & it's complex to use - you must have a trained person there to use it

Distinctive differences between individuals in their mtDNA makeup are most commonly found within which region of the DNA loop?

HV1 and HV2 These regions are noncoding, thus can accumulate mutations without affecting the viability of the cell

What should hair sampling sources include?

Hair sampling need not be restricted to humans. Carpet Domestic pets, sheep, cattle, horses, or other fur-bearing animals. Hair on fur coats, felt hats, or sheep skins sometimes used as car seat covers are also excellent pollen traps.

The frequency of an allele within a population can be calculated using _

Hardy-Weinberg Principle

Density means that it requires its own blood supply Bone is permeated by _ which transport blood

Haversian canals/ (Haversian system) Haversian canals run parallel to long axis of bone

proved that fingerprints are unique to the individual & that they are permanent, lasting for an entire lifetime

Henry Fauld

Taphonomic inventory includes what?

Identification of and completeness of all skeletal elements found. Whether skeletal remains are adult or immature. In the event of flesh remaining, x-rays and photography of element should be done. - amount of flesh remaining can tell us how long body was buried - fractures which show up during x-rays can help ID someone based on hospital records (such as fractures, etc)

What are the objectives of a forensic odontologist?

Identify human remains (individual and mass) Estimate age of the victim and perpetrator Analyze bite marks Archaeological cases Cold cases

Sporopollenin analysis allows scientists to do what?

Identify plant species Identify areas where these plants are present Can tell us more about the environment & how it changed over time Can help identify that suspect was present at a crime scene Identify where a bodies is buried, or where a crime took place

When might a body show evidence of more than one post-mortem process? (Decomp process, mummification or adipocere formation)

If environmental conditions surrounding body aren't uniform ex: body half buried face down in damp, wet woodland. Might show adipocere formation on front of body, but back of body might go through normal decomp process. If there is a mismatch of postmortem processes, area surrounding body must be examined because it might suggest the body has been moved, more than 1 burial site, etc

How might the same DNA end up on a database more than once?

If the suspect gives a different name or identification when arrested, their DNA will be taken & stored again, creating 2 different records and making it look like they are 2 different people

How can we know what type of "pollen fingerprint" to expect in samples from a geographical area?

If we know what the expected production and dispersal patterns of spores and pollens in a given region Forensic palynologists try to find a match between the pollen in a known geographical region with the pollen in a forensic sample. If it is a light pollen, it should have a large dispersal pattern (bc it can be carried by the wind). If the pollen is heavier, there will be a smaller dispersal area (dependent on how far the bee/animal can fly to disperse it). It's unlikely that 2 different areas would have the same pollen present

What are bite marks?

Impressions from teeth found on skin or items left at a scene. Usually outline teeth placement. Murderer in 1987 was identified from a bitten piece of cheese found at the scene Relatively new and expanding area of forensic odontology

Where are bite marks found?

Impressions left on food, skin or other items left at a scene. Porous surfaces that absorb the impact enough to make an impression Impressions vary Depending on the pressure applied, the impression will show accordingly. The more pressure there is, the more detail to the bite.

What is an example of an issue with expert testimony?

In 1998, Mark Dallagher was found guilty of murder on the basis of expert evidence that he had left a unique ear print on a window pane at the crime scene. After almost seven years in prison, Mr Dallagher was freed when DNA tests showed the ear-print was not his. The Commission said the case demonstrates why courts should have a statutory power to prevent juries hearing unreliable expert evidence.

Major difference in UK DNA database law & other countries' DNA collection laws

In the UK, DNA may be taken from anyone arrested & detained for a recordable offense DNA from an non-intimate sample (buccal swab or hair) may be taken without consent An intimate sample (such as blood) must have consent and an official witness present DNA from anyone arrested is kept on the database permanently

Why is"equality of arms" important?

In the adversarial system equality of arms is essential- bc both teams need access to the same types of facilities, such as forensic labs to test evidence. Important that both sides (prosecution & defense) have access to appropriate advise and assistance If required both should have access to facilities to undertake scientific work

Difference between adversarial & inquisitorial legal systems

In the adversarial system, the court solely acts as an impartial referee between the 2 parties rather than participating in the investigative proceedings as it does in the inquisitorial system. Inquisitorial system is used in countries with several legal systems, as opposed to case-law systems

Four types of teeth:

Incisors,Canine,Premolars & Molars Teeth differ in: Size Shape Root type

can be used to identify an exact shoe. However, these can change over time

Individual Characteristics

stage of decomp in which The cadaver appears fresh but is decomposing internally due to the activities of bacteria present before death (0-4 days)

Initial or fresh decay (autolysis) Wrapping/clothing, scavengers & other post mortem disturbances will effect the rate of decomposition, as will depth of burial (which slows the rate in comparison to if left on the surface)

best indicator of sex of an adult skeleton

Innominate morphology hip bone is largest irregularly shaped bone (illiim, ischium, pubis) Male - larger, more robust Female - larger opening between hips, adapted for child bearing and birth

Main methods to determine gender Non-metric methods : Metric methods:

Innominate morphology (shape of pubic bones of pelvis) Cranial morphology Maximum diameter of femoral head Maximum diameter of humeral head

How is rain/water taken into account when estimating PMI?

Insects are slow to colonize a body in rainy or wet environments.

What is the final step of an autopsy?

Internal examination

1st type of ossification, primarily in compact flat bones which don't have haversion systems skull & mandible in fetus are first to be laid down as a membrane.

Intra-membranous ossification formation begins on middle of bone/membranes and works its way out

Why is forensic palynology not typically used in court?

Issues with the collection of appropriate samples Little procedure for its use in court Lack of specialists (thus pollen evidence is typically not collected from the scene) Personal liability for forensic palynologists No training programmes available Need reference libraries to evaluate pollen evidence Funding

Why are there no written rules regarding expertise in forensics?

It can vary depending on the specialty - especially with new areas of forensics such as palynology, which does not have many training programs available to ensure academic qualification

What is "chain of custody?"

It is associated with each item of evidence & lists the signatures & dates of people who have been in contact with the evidence. The chain of custody is important because it helps prove the evidence hasn't been tampered with.

What is the structure of the mitochondrial genome?

It is circular, similar to that of bacteria

What are the pros & cons of zoogamous pollen dispersal?

It is good because if the pollen is found, there is a high degree of confidence that it is not an atmospheric contaminate. It is bad because it limits the chance of finding pollen on evidence. Few pollen spores are produced by each pollen, thus chances of finding pollen within a sample is reduced. Still, there is more pollen than with the self-pollinators

What differentiates the male mastoid process from the female's?

It is longer & thicker in males

What is plant barcoding?

It is used for quick identification of plants via referencing a library containing known botanical DNA sequences. A region of DNA can be used as a "barcode" if it contains enough variability to distinguish it, if it is short enough to sequence in a single reaction & contain conservative regions which can be used to develop universal primers. chDNA might meet these requirements

Why was the STR technique used to replace RFLP analysis?

It required large amounts of non degraded DNA & would take up to 2 wks to generate a profile STR and PCR can be used on one billionth of a gram of DNA and the analysis will only take a few days to process

Caution should be taken during bite mark analysis. Why is this? What assumptions are made?

It's assumed that human dentition is unique & that dental details can be accurately transferred/recorded on the skin Biting process is not completely understood. Many variables can cause distortions. Cadaver studies are aiding our understanding.

developed PCR

Kary Mullis in 1983 - used to amplify DNA present in a sample

_ increases the number of cycles in the PCR stage = increases the amount of DNA by 100-fold

LCN PCR - this is a solution for low copy # DNA

What are the advantages of LCN PCR?

LCN has improved the detection rates in volume crime such as burglary It is expensive but the improving detection rates makes it cost-effective Wider use will lead to cost reductions LCN has an impact on the type of evidence collected Allows contact trace evidence to be sampled

mature bone which is a series of microscopic layers Stronger than woven bone First type of microscopic bone we can visualize

Lamellar bone - collagen fibers are laid in alternating locations; we are looking for the layered structure of the bone Both cortical and trabecular bone have a lamellar structure but are organised differently

What differentiates the male mental eminence from the female's?

Larger and more pronounced in males than in females

the capture of fingerprint and palm images using an electro-optical computerised device.

Livescan - used to capture fingerprints & palm prints, which can be a unique identifier as well. Palmprints were not previously recorded using the old ink method

stage of death involving Purple-red discoloration of the skin, 6-12 hours after death

Livor mortis

also known as post-mortem lividity, settling of the blood in lower portions of the body/skin discoloration caused by the pooling of blood

Livor mortis occurs when heart is no longer pumping blood can show the position of the body after death & can help investigators determine if the body has been moved

What is involved in the Visual inspection part of the autopsy?

Look at all areas of body Record size/color of clothing items running a comb through the hair & checking for trace evidence

What is involved with looking for other available insect evidence (step 4 of determining PMI)?

Look for other insect evidence that might corroborate or contradict your PMI estimate.

In the western world Forensic Entomology was not born until 1855 when Dr Bergeret d'Arbois used entomological knowledge to help the police in Paris solve the murder of a child. How did he do this?

Looked at the presence of blow fly pupae and larval moths to determine time since death. Blow flies would have laid their eggs on a fresh corpse in 1948 Moths would have laid their eggs on the dry corpse in 1949

How do you calculate Accumulated degree hours (ADH)?

Looking at the development of the insect activity: ADH = total number of hours to reach developmental stage x (temperature - base temperature)

What is the most common, next most common, and least common fingerprint pattern?

Loops - most common (about 60% of all fingerprints) Whorls (~35%) Arches - least common (~5%)

If the ischiopubic ramus has a broad medial surface, is it M or F?

M

What are the methods used for estimating age using a child's skeleton?

Main methods: Dental development Fusion of immature bones Epiphyseal union

Example of using teeth for ID purposes:

Male teenager Stole a car and crashed it. The car caught fire and the teenager died. Initial identification was made using the phone found in his pocket. The identification was confirmed by comparing the dental records with the teeth from the scene

Drawbacks to facial reconstruction:

Many facial features are cartilage instead of bone- limits facial reconstruction. Average tissue thickness will be underestimated for people with significant fat. Key descriptive elements- hair length, facial hair, or glasses must be guessed.

How are plants used forensically?

Many scenes of crime are associated with plants: Murder/assault - often occur in parks/outdoor locations Burglary - plants on windowsills, in gardens Drug production War crimes (what season the war crime took place can be identified via pollen if we find mass graves) Can be used to confirm alibis. Can compare the pollen identified in a sample, but can also compare the chemical constituents in the soil to see if they also match a geographic location!

Which of the following cannot be used to detect the presence of a biological fluid? Luminol Marquis reagent UV light Phadebas test

Marquis reagent - this reagent is used only to test for drugs

Point of muscle attachment of the temporal bone which is longer and thicker in males

Mastoid process

How are shoe prints evidence?

Most perpetrators wear shoes. Footprints are almost always left, it is whether they can be located and differentiated from other prints which is important for forensic science. It can be difficult to ascertain which prints are relevant to the crime.

Why does DNA profiling take so long?

Mostly because labs have so many samples to process

Which of the following statements about forensic analysis is true? RFLP cannot be used for paternity testing DNA profiling examines differences in individual nucleotides STR analysis is also known as DNA fingerprinting MtDNA typing can't be used to identify a single suspect

MtDNA typing can't be used to identify a single suspect

Desiccation of a body, the normal process of decomposition, does not occur. Warm and dry conditions Can happen to bodies which have been concealed for long periods of time.

Mummification Skin will be shrunken Occurs in naturally hot climates. Can occur in temperate climates if the body is concealed in areas where dry air is circulated.

Can mitochondrial DNA & the Y chromosome be used to identify a single person?

NO - but they can be used to identify families & genetic ancestry

Do identical twins share fingerprints?

NO - even identical twins have unique fingerprints. In a case where identical twins are involved, investigators should look for fingerprints which will identify one of the twins

Are Y chromosome profiles unique to the individual?

NO - they are shared by paternal relatives, barring mutation They might help us narrow down the suspect pool but will not allow us to identify the guilty individual

Is a bomb blast an example of a volume crime?

NO it is a serious crime

Taphonomy includes examination of what?

Natural decomposition Peri-mortem trauma Animal activity Environmental factors Post-mortem trauma: Body processing,Secondary deposition & Cremations

Pollen and spores come in an infinite variety of shapes and sizes For this reason pollen and spores are often called_

Nature's Fingerprints of Plants < diameter of a human head hair 10-50 microns (µm) or millionths of a meter

the first species feeding on corpse tissue. Includes rue flies (Diptera) and beetles (Coleoptera).

Necrophages

new growth/abnormal patterns of growth in cells or tissue

Neoplasia Benign, not cancerous because they lack the ability to invade tissues, e.g. button osteoma - Malignant: Primary - relatively rare Secondary - more common,Majority destructive

Has the FBI granted access to CODIS?

Not at this time, due to genetic privacy

What is self-pollination?

Occurs in a small group of animals referred to as "autogamous", they are self-pollinating and are so efficient that little pollen is needed. Like pollen produced by submerged plants, the pollen of autogamous plants is of little value in forensic work because it is dispersed in minimal numbers.

species such as ants, wasps, and some beetles that feed on both the corpse and associated maggots.

Omnivores/Parasites and Predators Large populations of omnivores may slow the rate of corpse's decomposition by reducing populations of necrophagous species.

Describe a case in which forensic palynology was useful.

One of the earliest documented cases was a murder case in Austria. A man disappeared near Vienna but his body could not be found. A suspect was identified and mud from his boots were examined. A geologist, Dr. Klaus, was able to determine where the man had been walking due to pollen evidence. When confronted with this location, the suspect admitted to the crime & told investigators where the body was

_ in bone remodeling is the process of laying down new bone material by cells called osteoblasts. It is synonymous with bone tissue formation.

Ossification (or osteogenesis) All bones form by ossification of 1 or more centers, thus we can look at fusion of bone in order to estimate age

Certain conditions are restricted to the joints, which are fairly common. Some examples include what?

Osteoarthritis 'Spondyloarthropathies':Rheumatoid arthritis & Sero-negative spondyloarthropathies

Characterised by the breakdown of cartilage which covers the articulated joints Loss of this cartilage exposes the underlying bone surfaces

Osteoarthritis - most common form of arthritis ("wear and tear" arthritis), may result from Increased load bearing on normal articular cartilage Normal load bearing on weakened articular cartilage Gradually worsening disease for which there is no cure

three main types of cells involved in bone formation: _ - resorption _ - deposition of osteoid _- maintains the tissue

Osteoclasts Osteoblasts Osteocytes (thought to act as a sensor cell within bone)

Lamellae arranged around the Haversian canals are termed _.

Osteons Lamellae also seen Between osteons - interstitial lamellae Around the circumference of the bone - outer circumferential lamellae

Which of the following techniques is used to increase the amount of DNA present for analysis? gel electrophoresis RFLP STR DNA sequencing PCR

PCR (polymerase chain reaction)

How is STR analysis performed?

PCR is used to amplify the short tandem repeats within the region of interest of the mother & father of the DNA samples, which are then separated in vertical gel capillaries rather than the horizontal beds used for RFLP analysis. The number of repeats present will affect the amount of time it takes for them to be detected.

stage of death when the body becomes pale, 15-25 minutes after death

Pallor mortis

If one source of pollen is found, indicating a smaller dispersal area, or multiple sources of pollen are found, sometimes indicative of a larger dispersal area, it can be used to identify a region. How do palynologists use this information to do so?

Palynologists will take a map for each pollen type and identify the region where that pollen is likely to be, then lay the maps on top of each other to mixtures of pollen present within a region, then compare their findings to the sample from a crime scene. They can then go to the perceived crime scene to collect pollen, test it, and compare it to the pollen collected from the actual crime scene

Bloodstain which occurs due to gravity

Passive

What is the role of the expert witness?

People of specialist expertise - forensic scientist Experts can offer interpretations of the findings in the context of the case Encouraged to give opinion as well as factual evidence Provides information which falls outside the general knowledge of the judge or jury The question of guilt or innocence does not fall within the remit of the expert. ^The role of the expert witness is to use his or her experience and skill to provide impartial and unbiased evidence to the court.

Injuries sustained around the time of death

Peri-mortem traumas Sharp force, blunt force, or gunshot trauma Cannot prove cause of death-Not allowed - role of pathologist Possible to identify injuries and/or potential weapons

Detects the presence of amylase. An enzyme present in high concentrations in human saliva.

Phadebas Amylase Test

Compare & contrast the strengths & weaknesses of DNA extraction kit versus the phenol-chloroform extraction?

Phenol-chloroform extraction is good for high molecular weight DNA samples, as well as for extracting DNA from tissue (muscle, liver etc). Labs may also create their own solutions, because they are not specific to a manufacturer as they are with extraction kits. Phenol-chloroform extraction does, however, require the use of hazardous materials & the risk of contamination is relatively high due to the need to transfer the sample from tube to tube. DNA extraction kits do not require high molecular weight DNA samples, nor do they require the use of hazardous materials. The risk of contamination is relatively low, because all reagents & necessary materials are provided in the kit & may be disposed of after usage. The downside of extraction kits is that it can be difficult to process multiple samples due to how many washing steps are required. Additionally, labs are unable to create their own solutions, as they are specific to the manufacturer.

One early summer's morning, a man who is walking his dog discovers a dead body in a field along a public footpath. The weather is warm & sunny but there has been recent rain & more is forecasted. A brief inspection reveals that the victim is quite clearly dead and appears to have suffered multiple stab wounds. The man calls 911 on his cell phone to request police. The first reporting officer arrives, followed shortly by the crime scene analysts. Describe 2 different methods you could use to record this crime scene & discuss the benefits/limitations of both.

Photographs could be used to record the crime scene. The benefit is that _ & the limitations are _ Sketches can be used to record the crime scene as well. The benefits are _ & the limitations are _

Important to forensic anthropologist as will be evident in remains-Traceable

Reconstructive surgery Can occur anywhere in the body Common examples: Hip replacement Pinning of bones

The visual inspection/external exam of the autopsy includes looking at what?

Physical attributes Scars and/or tattoos Evidence of wounds/bruises All findings diagramed and recorded in detail Stowaway identification (when plane came in to land, body fell out of plane - person survived the flight but died from the fall. they were identified by a tattoo photographed & shown to friends/family)

How do forensic scientists work with the prosecution?

Police officer often has direct contact with forensic scientist involved in the prosecution case from the beginning possibly even at the crime scene when evidence is initially collected. Forensic scientists for the prosecution conducts in-depth examination of all items.

How are pollen & spores important forensically?

Pollen and spores are highly resistant to decay (being found in rocks many millions of years old & persisting in soil, dirt & persisting on/in other materials for many years (e.g. buildings, woven cloth, food, drugs, counterfeit money, on our clothes, in our hair, etc). Each plant type has distinctive pollen that can be distinguished from pollen of other plants - important for forensics - the geographical area accumulating pollen & spores for millions of yrs will look different from other geographical areas, which will have different types of pollen & different concentrations of it

Why is pollen forensically useful?

Pollen is microscopic & virtually indestructible - making it useful in crime scenes because it is not subject to decay like other evidence The pollen structure is unique to each species of plant, thus will only be present in certain areas and can link suspects to crime scenes. Did it come to the area because it was attached to animal for pollination? Was it brought there by the suspect or victim? The pollen on the victim should match the burial site; if it doesn't it is suggestive of more than 1 burial site

What is the difference between PMI and time of death?

Post mortem interval is restricted to the time that the corpse or body has been exposed to an environment which would allow insect activity to begin. Closed windows Body in box or bag Cold temperatures Deeper burial

Injuries sustained after death

Post-mortem trauma Dismemberment:Concealment/Transporting Secondary deposition (Perpetrators may have second thoughts regarding first deposition site,Remains out of anatomical order) Cremation

Individual Identification involves what?

Postmortem description is generated(X rays and radiographs) Positive identification is compared to ante-mortem data Negative identification, a biological profile is generated

If it's a felony, what happens after arraignment?

Preliminary hearing/grand jury: evidence is brought before grand jury for them to decide if it is sufficient to indict (pursue conviction). They listen to the prosecutor & then vote. If majority rules in favor of indicting, they will proceed. If not, the person could be released. If they decide to indict, they move to the pretrial arraignment. The suspect is informed of the grand jury's decision, charges are formally brought against them, and the rest of the court dates are set. The trial occurs (CSI experts are brought in to testify regarding the evidence & judge/jury decides if the person is guilty or not guilty). At the sentencing hearing, victims and other people testify about how long the person should be in prison or what their penalty should be. The judge listens and decides how long they will serve, what fines they'll have, etc. After sentencing, the prisoner may decide to appeal at which point you go back to the trial phase. Otherwise, the person is sentenced & set to prison or probation. This whole process may take yrs, so this sentence may include partial credit for time already served.

The 1st stage in an investigation is to preserve the crime scene. Why is this so important for the rest of the investigation?

Preserving the crime scene is crucial, because without this step a case cannot be made to try before a judge. Preserving the scene prevents contamination of the scene, tampering with/removal of evidence and accurate testimonies from witnesses. Part of preserving the scene involves identifying eye witnesses & immediately separating them from each other & from the scene. This allows accurate testimony to be made without influence from other witnesses or the state of the scene. If inside, an officer may guard the door of a scene & record who enters & exits. This prevents the prosecution/defense from making accusations of evidence tampering. Lastly, if the scene is outside or if bad weather is impending, preserving the scene is a necessity to gathering all evidence & maintaining its integrity.

What is the marquis reagent used for?

Presumptive DRUG testing

_ teeth sprout from milk buds and are temporary. Once they fall out, _teeth as seen on the other side appear. General rule - Every_months _teeth will erupt.

Primary / permanent every 6 mos 4 teeth erupt - Lower teeth usually erupt before the upper teeth.

Considered one of the most reliable method of adult age estimation. What changes occur with age?

Pubic symphysis Located at front of pelvis where the two pubic bones meet The thick cartilaginous end plates will decrease to a thinner layer with age

stage of decomp in which The cadaver is swollen by gas produced internally, accompanied by the odor of decaying flesh (4-10 days)

Putrefaction or bloating Gases being produced by body begin to build up which causes the distended/bloated appearance. These gases/fluids will escape through the natural orifaces as the pressure builds

The original DNA profiling method, called "DNA fingerprinting"

RFLP DNA is cut by restriction enzymes which can identify specific short sequences of DNA (usually 4 nucleotides in length) - Because everyone's DNA is different, the enzyme will cut in different places depending on the person. Thus, different fragment lengths are generated which are unique to that person.The fragments are separated via electrophoresis. Visualization is enabled by staining, using dyes which bind to the fragments.

What are the 2 main methods of DNA profiling?

RFLP (restriction fragment length polymorphism - the first kind used for forensic science) STR (short tandem repeat analysis - a more modern technique)

DNA profiling is an advanced technology which has evolved from the _ profile to the _ profile

RFLP / STR

What is course documentation & what does it include?

Required to document every action undertaken and note every person who assists with the work. Should include Telephone calls and written correspondence. Notes to assistants regarding work carried out. Record of examinations carried out, tests undertaken, interpretation of results. Drafts of the final report, a copy of the report itself.

Autoimmune disease primarily attacking joints Results in inflammation of synovium and destruction of articular surfaces

Rheumatoid arthritis Common disease,Causative agent unknown Cytokines involved stimulate osteoclastic activity,May result in osteopaenic bone Understanding the process of destruction can help us determine how long the person has been suffering from the disease, aiding in identification

The study of the uniqueness of friction ridge structures and their use for personal identification.

Ridgeology: The term "ridgeology" was coined by Sergeant David Ashbaugh to describe the scientific evaluation process used for friction ridge identifications.

stage of death involving stiffening of the limbs, starts 3-4 hours after death, with a maximum at 12 hours, dissipates at 24 hours

Rigor mortis

What is the process of rigor mortis & what causes the stiffening of the limbs?

Rigor mortis ends when autolysis takes over. The actin & myosin filaments within muscle are the main proteins involved in rigor mortis. The membranes of the muscle cells become permeable to calcium ions; the calcium ions. Because ATP levels drop in non-living muscle, calcium ions are not released from the cell, actin & myosin remain linked together, and the muscles remain contracted.

mtDNA was important in identifying members of the _ family

Romanov

the most abundant protein in chloroplasts and probably the most abundant protein on Earth

RuBP carboxylase or rubisco, the enzyme which catalyzes the first step of the Calvin Cycle, or dark reaction

Technique used for DNA profiling in UK

SGM Plus: it tests 10 markers known as STR and gender marker

Mass identification includes what?

Same process is used as individual identification Organization is crucial Family is asked to come identify the body, and narrow down the pool of victims.

_ convenient to grave should be set up for sifting through material from grave. Knowledge of _prior to excavation is helpful. _should be used.

Screening area (sorting through evidence from soil material such as bullets, fibers or hairs. can help identify perp or determine cause of death) position of body (if we can estimate this, it can aid the excavation process & what we can expect when we're uncovering remains) Small tools (trowels, brushes) - motorized equipment can cause damage - damage to the remains should be kept to a minimum.

What else can footprints tell us?

Sequence and manner (walking, running, limping, staggering) in which the impressions were created. Links between crime scenes, e.g. the same individualss committing several crimes in one evening. The type, size and areas of specific wear on the shoes. Certain seasons or weather conditions lend themselves to the creation of footprint impressions than others. Soil trapped in soles can also give useful leads, such as soil pH, specific minerals or heavy metals in the soil, the presence of seeds or pollen grains.

large carrion beetles that feed on both carrion and fly larvae

Silphids Even though adults have been recorded feeding on carrion, they cannot survive on it alone, and die if they do not have access to maggots.

• Explain why sinking speed is an important consideration when studying pollen and spores at a crime scene.

Sinking speed will be an important factor in determining the dispersal area of a particular pollen. Pollen grains of different masses will fall to the ground at differing speeds. Those of lesser masses will fall to the ground more slowly and vice versa. The longer it takes for pollen grain or spore to fall to the ground, the more opportunity it has to be carried by the wind. Thus pollen grains of lesser mass will be subject to greater dispersal areas and will not be as conclusive as to what area they originated from.

first person to use fingerprints to link documents to people

Sir William Herschel (used fingerprints on contracts in India)

What is nuchal crest & how is it different in males & females?

Site of attachment for several muscles of the neck More pronounced in males

Individual Characteristics of teeth

Size of tooth Shape of tooth Shape of root Placement of tooth Quantity of teeth Combinations of dental work done: Crowns,Extractions,Bridge,Fillings & Root canals

stage of death involving drying of the skeletal bones

Skeletonization

At the dry stage of decomposition, what insect activity is there?

Skin and bones Insects with the ability to digest keratin (clothes moths and dermestid beetles).

What does sediment evidence include?

Soil, dirt, and dust, common elements at almost every crime scene. Samples of dirt collected from the clothing, skin, hair, shoes, of a victim or suspect might prove useful in linking the victim with the location where the crime occurred

What are examples of miscellaneous pollen samples and how might they be used?

Someone might suspect the origin or age of a shipment of crude oil or coal samples. Some types of packing materials used in shipping products, such as shredded paper, straw or cardboard are also useful places to search for pollen. Commercial honey purported to have been made from the nectar of specific plant.

Example of pathological conditions which increase with age - do age-related pathologies provide proof of age?

Spinal oseophytes over the age of 35 Age-related pathologies are not definite proof of age; they serve as indicators only. Can help narrow age estimates

3 police officers are asked to search a large field for evidence. Which search pattern would be LEAST helpful for this search? Grid, spiral, zone or parallel lines

Spiral ^This type of search usually only involves one person & should be conducted in small areas.

Category of diseases which cause inflammation throughout body

Spondyloarthropathies (spondyl-, spine) Main target areas:Spine&Joints where ligaments/tendons attach Include diseases such as:Rheumatoid arthritis,Ankylosing spondylitis-Differ with presence or absence of rheumatoid factor

How do you determine the PMI?

Step 1. Collect samples of the insects present. Step 2. Determine temperature history at crime scene Step 3. Estimate time of egg laying Step 4. What other insect evidence is available?

What happens during a trial?

Swearing in of the jury Prosecution will open its case - outline evidence Witnesses for the prosecution will be called (examination-in-chief) Witnesses may be questioned by the defence (cross-examination) The defence will then present its case Witnesses will be called Witnesses questioned by prosecution Closing speeches (prosecution lawyer, defence, judge) Jury verdict

How is a database utilized when there is a known suspect?

Take a DNA sample from subject & compare it to DNA from crime scene - database unnecessary

What is The Universal System for analyzing teeth?

Teeth are given a specific number. (Primary teeth are given specific capital letter) Any dental work done on surface is noted. Sheets kept on dental file forever. When person is missing, files are transferred to the missing person's office.

As studied at the Body Farm in TN, which are the most important environmental factors which affect corpse decay? What other factors are there?

Temperature,Access by insects,Depth of burial Chemical-- embalming agent, insecticides, lime, etc. Animals disrupting the corpse

Wolff's law states what?

That bone is living tissue, constantly being remodeled

If the name of a DNA region has a D#S#, what does it mean?

That it is non-coding The # after the D relates to the chromosome The # after the S relates the section of the chromosome Short tandem repeats on coding regions will not have the D#S#, but will be named after the gene on which they are found.

If a single peak is present in STR analysis, what does that mean?

That the person is homozygous - the same number of repeats are present on both chromosomes. If more than one peak is present, there are a different number of repeats on each chromosome (heterozygous). This would result in different fragment sizes which would be detected at different times, generating multiple peaks

What is the process for chloroplast DNA analysis?

The DNA is extracted from each species, then amplified using RAPD-PCR. The samples are then run of an agarose gel using gel electrophoresis and the gel dyed and photographed (similar technique to DNA fingerprinting-RFLP).

Give 2 explanations why a DNA profile at a crime scene might match an innocent person

The DNa profile at a crime scene may match an innocent person if the person had been at the scene prior to the incident. Additionally, the DNA sample from which the profile was generated may have been contaminated. For instance, if the lab technician contaminated the sample due to not wearing proper protective clothing, their DNA would be present in the sample and would be reflected in the profile.

the USA national fingerprint and criminal history system

The Integrated Automated Fingerprint Identification System (IAFIS), run by the FBI Extremely effective system - we can an enormous # of fingerprints on the database, generates a match (or determines that there is no match) in 27 minutes. the system is available 24/7/365 - this speed and availability has a great impact on the speed of the investigation process

When trying to identify a male perpetrator of a crime, which of the following is NOT an advantage of Y-chromosome analysis? The Y haplotype is shared by paternal relatives The Y chromosome can be analysed in mixed samples if the perpetrator is male Method is fast & similar to STR analysis It is useful because males commit the majority of violent crimes

The Y haplotype is shared by paternal relatives

What is the difference between the amelogenin gene on the X & Y chromosomes?

The amelogenin gene is longer on the X chromosome. Because females are XX, their amelogenin will travel through agarose gel at the same rate, generating a single band on the gel. The amelogenin gene on the Y chromosome is shorter, thus will travel further through agarose gel electrophoresis. Because males are XY, this will generate 2 bands on the gel - one band for the longer amelogenin present on the X and one band for the shorter amelogenin present on the Y

What if there are no dental records? How might forensic odontology be used then?

The body of a child was found. Dental records confirmed child was approximately 5 years old. Missing 5 year old was reported. Child had never been to a dentist. Skull x-ray from a recent injury confirmed an abscess on the lower molar. This was confirmed in the jaw of the body that was found. Identification based on medical records not dental records

How can the brand of a shoe be used forensically?

The brand of the shoe can be tied to the shoe pattern to determine the type of shoe. If the particular shoe is very rare, this can help us narrow our suspect pool.

the first beetles to arrive at a corpse, soon after the body begins to putrefy.

The carrion beetles There are over 200 species in this family, but the ones that eat dead flesh are those that belong to the subfamily Nicrophorinae

What are the requirements for quality & how is a competent forensic scientist chosen to testify?

The forensic scientist:Requires a basic background in science, receives Detailed training is provided on the job, must show what degree they have (a master's or usually a PhD are typical, though newer areas of forensics such as palynology may not have a degree available. if evidence of academic understanding is not available, they may leverage their experience in the field) The witness has to show experience in their area of expertise - this is determined by the judge/prosecution/defence Expert witness directories are available

Describe the difference in blood spatter pattern that you would expect to see if you dropped a single drop of blood in the following 2 situations: A droplet of blood which had a volume of 5ul vs.25ul A droplet of blood which you drop from a height of 5cm vs a height of 40cm

The larger the volume the greater the diameter of the stain. So the 25ul would produce a larger stain. The droplet of blood dropped from a greater height should have a greater diameter than that dropped from a lesser height.

When looking at post-mortem lividity, what are the lighter patches of skin indicative of?

The lighter patches of skin will appear where the body was in contact with a hard surface. Darker discoloration will occur due to pooling of red blood cells.

For a forensic investigation, explain why it is important to calculate match probability for a DNA profile

The match probability is calculated by 1/genotype frequency & states the likelihood that 2 unrelated people selected at random would share the DNA profile

What are the issues with fingerprint analysis?

The method of determining a match is disputed, as some believe that a quantitative method (requiring a certain # of points) should be implemented rather than the qualitative method. There is also debate over the method of collecting and interpreting fingerprint evidence. Ex: Shirley McKie was convicted of perjury when she said she wasn't at the house of a murder victim, when experts confirmed that her fingerprint was found on the doorframe. She actually had not been at the scene, so the conviction was later overturned & she received compensation

Footprint impressions from casts and/or by photography will give investigators information about what?

The number of people present at the scene (perpetrators). Points of entry and exit. Positions of perpetrators(s), victim(s) and witness(es). Direction(s) of movement/travel and pathway(s) through the crime scene. Time period, from short-lived impressions in frost, snow, dew.

What does it take to determine a fingerprint match?

The old system required 16 points to match Other countries use 8, 10 and 12 points or no numerical standard Recently, a non-numerical standard has been implemented. The fingerprint match is a matter of opinion by the expert & therefore cannot be quantified

Which evidence could be used as probative evidence in a courtroom (prosecution wants to prove that professor plum stabbed colonel mustard in the conservatory)? The only fingerprint found on the dagger used to murder him matches that of professor plum. A report from a forensic scientist stating that DNA could not be collected from the dagger. Evidence that colonel mustard & professor plum had dinner the week before. All the above.

The only fingerprint found on the dagger used to murder him matches that of professor plum. ^Probative evidence provides support to one side of the case, either supporting the prosecution or defense.

If the pollen found at the scene does not match a suspect,what does it mean?

The person wasn't present at the crime scene, or the shoes/clothing being analyzed were not worn to the scene.

At a crime scene you find blood spatter in the kitchen. You decide to collect a swab of blood from a tile on the kitchen floor as evidence. Describe what you would collect, or use as a positive control, and also what you would collect as a negative control.

The positive control would be collected blood from the victim. The negative control would be an area of the tile without blood on it. Then you could see if there is anything on the tile, such as bleach, which would give a false positive result.

What is the role of the prosecutor?

The prosecutor is an administrator of justice, an advocate, and an officer of the court. The duty of the prosecutor is to seek justice, not merely to convict.

How is chloroplast DNA used to identify a plant genus or species?

The random amplified polymorphic DNA (RAPD) method can be used to identify the species of forensic biological samples by providing a simple, fast and sensitive fingerprinting method in species identification for crime scene evidence or food products of endangered species.

Why are familial searches so effective in the UK?

The search isn't based on genetics alone. Age and more importantly, geographic location are combined with genetics to create a ranked list of potential relatives of an unknown forensic profile.

How is a burial site typically searched?

The surface is divided into a grid, then debris is removed in order to uncover the remains. The latitude & longitude & depth within the ground must be noted when uncovering the remains

How might soil analysis (particularly petrology) in conjunction with pollen be used to refine or strengthen an association?

The tires of a car suspected to be involved in a crime may be analyzed by collecting both soil and pollen from them. The soil characteristics and petrology can be used to redefine the search area using geology & soil maps, while the pollen & vegetative remains can be used to target woodlands with a particular species mix. The soil evidence provides a geological match while the pollen provides independent evidence of vegetation type, providing a combination that may be rare or unique.

What is pollination?

The transfer of pollen from the male anther to the female stigma Pollen from grass can be transferred by wind. Other pollen is transferred by insects in insect pollination. This produces variable offspring, creating diversity and variation among populations

Variables affecting size and shape of a bloodstain:

The volume of the individual drop The dropping height The nature of the target surface

Looks for natural sources of radiation

Thermal imaging - identifies warm objects within a location. This works best at night but only the surface temp is detected. A body buried too deeply will not generate a thermal image. The limit of the infrared detection depends on the material present. Thermal images will also capture live animals, which can make it tricky to differentiate between living organisms and dead.

What about bite marks can make them difficult to assess?

They are complex. Bite marks can be found on people at the scene or on other objects The bite mark could be human, animal, or self-inflicted It is essential to ensure that evidence relating to the injury id documents, collected, preserved, analyzed and interpreted following appropriate protocols.

How is forensic scientists' involvement with the defense different from that of the prosecution?

They are typically called upon by the legal team. Therefore they may have no involvement int he case until after the initial forensic examination has been completed, and often will not be able to see the items of evidence in their original condition when they were first collected. This discrepancy must be taken into account when drawing conclusions. Funding for forensic testing of the samples may also be limited, as it is coming from the defense team. They typically have much less $$ to work with in comparison to the prosecution. Thus, the defense will often pick holes in the laboratory work of the prosecution

Why do animals pollinate plants?

They get a REWARD: food, Nectar - a sugary solution Nectar concentration matches energy requirements of the pollinator. Pollen - is high in protein, some bees and beetles eat it. Sterile pollen is typically tasty, attracting insects to eat it. The normal/fertile pollen will attach to the insect while it is eating the sterile pollen, allowing it to be transferred to the next plant it goes to eat sterile pollen from.

If a person's DNA doesn't match that found at the scene, what should be done?

They may have STILL committed the crime (may have worn gloves, mask, hat etc to prevent leaving DNA at scene). We should still confirm their alibi & check other items of evidence - once this is done they may be eliminated from the investigation

What is controversial regarding the UK's method of "testing" experts to ensure that they are reliable/trustworthy?

This is controversial, bc the expert witnesses are called to the court on the premise that they are experts in the field having specialist knowledge of the subject matter. How would the judge be able to determine if the evidence is "reliable" or "trustworthy" since the judge will not be an expert in all areas of forensic science?

What are individualizing features?

Those which can be examined to confirm ID of remains Epigenetic traits Pathological conditions Ante-mortem trauma

At a crime scene you identify a substance you believe to be urine. You send it to the forensic laboratory for testing but they say they are unable to generate a DNA profile. Explain why it might be difficult to do so.

Thought it is easier to obtain a DNA profile from urine than from feces (due to less bacterial interference with PCR), there is less DNA content within urine. This makes it difficult to generate a DNA profile.

Shoeprint made in soft material (dirt, snow) Requires making a cast of the print Composition of dirt or snow will determine the detail of the impression

Three dimensional impression As with the 2D print ,you start by photographing the print. Then you try to preserve the print for analysis by making a cast of the print (with plaster of paris or dental stone). You must first seal the print (such as with hairspray) so that the liquid poured in doesn't move or damage the print. Once the cast has been set, it can be removed & then left for another 24 hrs to dry completely prior to brushing off any soil or debris attached to the cast.

What is on the x axis of an STR analysis graph?

Time - the time it took for each fragment to move thru the gel & be detected by the detector

What is the role of the witness?

To place before the court information which may be relevant to the case in question. Usually limited to evidence of facts that have formed a direct part of their experience. Generally not permitted to give 'hearsay' evidence.

If a presumptive test is positive, what is the next step?

To take it to the lab for DNA extraction (isolation of DNA is the first step prior to DNA profiling, cloning, disease diagnosis, DNA sequencing, GMOs & environmental testing)

Dirt or other material picked up by shoe and deposited onto flat, hard surface. Variety of surfaces and materials deposited makes recovery of these prints complex.

Two dimensional footprint (visible)

Can leave behind barely visible impressions in dust Can leave impression in polish or wax

Two dimensional print (latent) Different reagents can be used to make the latent prints visible. For example, if the footprint is in blood, luminol can be used to enhance the print. This can be done at the scene or if the print can be removed (such as on a tile) it can be done back at the lab. It can be useful to perform the enhancement at the scene, because it can then be made clear how someone moved about the crime scene.

Processing a scene with buried remains requires considerable effort and expertise. How many perimeters need to be set? What happens next?

Two perimeters need to be set: 1st for immediate grave area 2nd for scatter area Carefully uncover the remains and artifacts Study the natural soil layers - possibly used to date the burial site. Filter the soil and debris to identify trace evidence at the scene. *Each stage must be documented with photographs, notes & sketches

What are the best pollen samples? What other samples can be collected?

Types of forensic-palynological evidence material: 1. Sediments 2. Hair and Cloth 3. Illegal drugs 4. Miscellaneous (food, cargo etc) Best are soil samples Also hair washings Smear stains on clothing

Which database has DNA from the largest percentage of its population?

UK's database - (5.2% versus 0.5% in US) This is partly due to their laws regarding DNA collection It includes individuals convicted of a wide range of crimes (anything related to a prison sentence) It doesn't matter if they were never convicted or later found innocent - once they are arrested, their DNA is placed on the database & can never be removed. In many other countries, your DNA is only stored once you have been convicted & found guilty and even then it is only for serious crimes

Structure of the federal court system:

US district court (trial courts which hear cases for the 1st time) Court of appeals (reviews cases from the district court which have been appealed- called an "appellate court" as it reviews & reverses decisions of lower courts) US supreme court (highest court which reviews selected cases from the Court of Appeals - this is where judicial review occurs)

Arthropods are typically associated with what type of crimes?

Usually violent crimes such as murder, suicide, and rape, Physical abuse and contraband trafficking.

How is DNA from pollen useful & what are the potential drawbacks?

Valuable for linking an individual to a crime scene or physical evidence to a geographic location. Can be used to determine if a crime has tken place. Can be used to identify a plant species. Botanical trace evidence often does not contain the necessary morphological features to link it to the parent plant.DNA analysis can be performed to identify the tree/plant from whence it came

In looking at fusion of immature bones to determine age, how are the vertebrae assessed? What changes can be expected to emerge with age?

Vertebrae Form from three main centers:2 neural arches and centrum (a) Neural arches fuse first (b) 2-4 years Neural arches then fuse to centrum (c) 3-6 years

Low copy # DNA refers to what?

Very low levels of DNA and degraded DNA result in a poor quality or negative result- touch DNA is an example In this case PCR would not be able to amplify it to high enough levels to enable profiling.

What does looking at Cranial morphology to determine gender involve & what is the general rule used?

Visual examination of features Assigned female or male General rule Males larger more robust Females gracile

What are the key questions that must be answered at each crime scene?

WHO was the victim/intended victim, perp & witnesses WHAT were the events that led up to the crime, motive, modus operandi, tools, objects removed from scene WHEN did crime occur, key events that led up to crime WHERE did crime occur, perp enter/leave scene, perp stand during commission of crime, people within the scene, witnesses stand, victim found

One of the first things that must be done once remains are obtained is determining what?

Whether the bones are human or non-human Teeth identification is critical - these are different sizes depending on the diet One of the main ways is to look at the skulls - very different between animals & humans

What is the most inefficient form of pollen dispersion? What plants are part of this group?

Wind pollination a wide range of producers such as the gymnosperms, angiosperms and spore-producing plants such as fungi, ferns, and mosses Cannibis pollen is produced in large amounts, and is present on many peoples' shoes even if they are not associated with the drug trade. Trace amounts could have come from almost anywhere as a result of "random air dispersal" of that plant's pollen.

Vast quantities of this type of pollen is produced (liters) and is Spread over wide areas, 100s miles

Wind pollination: Grass Beech Cannabis

forms fetal skeleton, which is gradually replaced by lamellar bone collagen fibers laid down in a disorganized pattern, making it weaker than lamellar bone

Woven bone (primary/reparative bone) Characteristic of rapid bone formation Can be seen in adults in response to injury or disease May form under the periosteum in response to infection Produced during fracture repair

Microscopic bone structure which may be seen in adults in response to injury or disease

Woven bone (primary/reparative bone) May form under the periosteum in response to infection Produced during fracture repair

What is included in hair/cloth samples?

Woven cloth and ropes make good traps for pollen and spores. Hair and fur is one of the very best pollen and spore traps: Pollen in the wind becomes trapped in the open spaces between individual hairs. A hair or fur sample can be washed and drained through filter paper to trap the pollen within it. The water that drained can be filtered as well to trap additional pollen present.

Other factors which affect rate of decomp

Wrapping the body (sign of criminal activity - can include plastic wrap, metal wrap, fabric such as carpet - aids in transport & hides body from view) - This helps exclude the oxygen, possibly insects/animals as well which could speed up decay rate Burial underground Burial underwater ^Burials are also associated with criminal activity. Decomp is generally 4x slower when buried in soil, due to chemical actions & lower abundance of microorganisms. The microorganisms will vary considerably depending on location & depth. In water, a body will fill with gases during the decomp phase, causing it to float to the surface exposing it to oxygen and colonization by insects.

paternally inherited

Y chromosome We can specifically look at male DNA profiles using the Y chromosome.

Describe the similarities & differences between Y-DNA analysis and autosomal DNA analysis & their value to forensic investigations

Y-DNA analysis is similar to autosomal DNA analysis in that it is analyzed via STR typing. In autosomal DNA analysis, there are 2 chromosomes examined for each STR region of interest. This will generate 2 #s per STR region. In Y-DNA analysis, only one chromosome is examined for each STR region of interest, thus producing a single # for each region. Additionally, the Y-chromosome is not unique to the individual so can only be used to reduce a suspect pool. Autosomal DNA profiles are unique to the individual (except for identical twins) so can be used to conclusively identify a single perpetrator

Can fingerprints persist after death?

YES, which can prove useful for post mortem identification NO 2 FINGERPRINTS ARE IDENTICAL. No 2 fingerprints have been found to be the same to date, even when comparing relatives or identical twins.

80% of pollen is dispersed via _. What is involved in this?

Zoogamous plants: pollen is transported by insects or animals. Because of the efficiency, pollen productivity is low Potential value to forensics is excellent. These pollen grains have some of the most durable coats and will remain preserved for long periods of time, less susceptible to destruction. Produced in fairly low amounts, thus not too much potential of contamination of different areas. If the pollen is found in an area, it is likely that it is the origin of the forensic sample.

Each state has what kind of court?

a district court - each territory of the US has a district court as well They are organized to form 12 regional circuits, with a court of appeals for each circuit. The supreme court is located in washington DC

What is the structure of the chloroplast's membraneous exterior?

a double outer membrane. A smooth outer membrane which is freely permeable to molecules and a smooth inner membrane which contains many transporters: integral membrane proteins that regulate the passage in an out of the chloroplast of small molecules like sugars and proteins synthesized in the cytoplasm of the cell but used within the chloroplast.

What is DNA profiling

a method of identifying an individual by looking at unique characteristics present in their DNA. DNA differs due to the presence of different alleles - the entire genome is NOT sequenced, because it is unnecessary & extremely time consuming. specific regions are selected which are shown to accumulate mutations

What is an important consideration when thinking about implementing familial searches in the US?

a relative must already be in the database in order for the search to identify them as a potential relative. Even if the relative is in the database, it's possible they might not be included in the ranked list produced by the familial search. A familial search will always generate a ranked list of potential candidates. Because the US DNA database generally only contains individuals associated with serious crimes, it is more likely that those on the list could be the suspect (vs the UK's database which contains info on anyone who's been arrested)

applied to fingerprints which consist of a combination of 2 or more patterns, or a pattern that doesn't fit into any of the classified categories

accidental whorl (rarely do you see more than 1 of these present)

There was an article in Science which called for "DNA disclosure"- allowing scientists to access profiles on databases for research & quality control. Why might this be a good idea?

according to 1 study, *error rate is 1 in 300 profiles* - there is much room for improvement! if we don't know how errors occur, we can't put mechanisms in place to prevent or correct these errors *to verify STR frequency estimates* the early frequency studies may not represent entire current population; could mean that RMPs presented in court are incorrect

Created when an exposed blood source is subjected to an action or force, greater than the force of gravity

active bloodstain (arterial, cast-off, impact spatter)

Quantification of DNA obtained is accomplished how?

agarose gel electrophoresis

stage of death involving cooling of the body, after 8 hours

algor mortis

How many people in a town of 200,000 might be genotype 2,2?

allel frequency = p^2 = (0.26)(0.26) = 0.0676 (0.0676)(200,000)= 13,520

genotype frequency = what?

allele frequencies multiplied together

If the allele frequency is as follows, what is the expected frequency of genotype 4,6 in the population? In a town of 200,000 people how many would be expected to have this genotype? allele (# of repeats) allele frequency 2 0.26 3 0.01 4 0.43 6 0.09 8 0.15

allele frequency = 2pq = 2(0.43)(0.09) = 0.0774 expected # of people with this genotype in a population of 200,000 = (0.0774)(200,000) = 15,480

Latent prints may be collected by revealing them with a dusting of_ or _ powder and then lifted with a piece of _.

aluminum or black powder / clear tape Camel hair was the most common animal hair used to make fingerprint brushes. But now many brushes are made out of fiberglass or other animal hair such a squirrels'.

very important in a DNA profile, because it is used in sex determination

amelogenin - shows whether the suspect has two X chromosomes or an X & Y- it is used only for sex determination, not for the rest of the profile

trauma suffered in life that is either healed or has begun healing

antemortem trauma most common antemortem trauma are fractures (Accidental or indication of previous attack) Other examples include reconstructive surgeries Can provide an understanding of the individual's lifestyle

What is a mass disaster defined as?

any event that occurs with little or no warning causing death or injury resulting in disruption of the community.

Accounts for 5% of all fingerprint types the simplest type of fingerprints that are formed by ridges that enter on one side of the print and exit on the other. No deltas are present.

arches: plain & tented

self digestion of body cells

autolysis walls of cells give way, contents of cells flow out, rigor mortis is ending because autolysis is taking place, resulting in the breakdown of the muscle. The muscle becomes soft and gives way to the other stages of death

Three main processes involved in natural decomposition:starts from the moment of death

autolysis: breakdown of tissues by body's own chemicals and enzymes putrefaction: breakdown of tissues due to bacteria; causes release of gases/odors which attract insects & animals insect activity: insects attracted, lay eggs in body, eggs mature into larvae & insects which feed off body & further breakdown tissues & organs

outdated forensic tool used to reduce suspect pool

blood group typing - because a blood group is shared by many members of a population, it is not discriminatory

Bloodstains known as cast-off bloodstains are created when _

blood is flung off a blood-soaked object Cast-off patterns are produced when blood transfers from a source to a secondary object which is then moved, and the blood comes off that secondary object. The object could be a weapon.

When the corpse develops an odor, what insect will be found there?

blow flies & flesh flies

When the corpse is fresh (first 3 months), what insect will be found there?

blow fly

Wound caused by blow with heavy object

blunt force trauma - we can use the size of the trauma to determine what kind of object could have created it - then search the suspects' house to see if there is a matching object present

In latent fingerprints, the ridge structure is reproduced on an object in sweat, oily secretions, present on the fingers. Most latent prints are colorless and must therefore be "developed," or made visible, before they can be preserved and compared. How is this done?

brushing them with various gray or black powders containing chalk The latent impressions are photographed or lifted using adhesive surfaces of tape. The method of development depends of the surface type and color.

A false positive result is best described as one that is given:

by a substance other than what is being tested for OR when the substance being tested for is absent

mtDNA is analyzed how?

by looking at the nucleotide sequence (looking at individual nucleotides rather than STRs) and doing comparisons with reference sequences to identify where mutations are present most mutations occur in the D-loop (within it are the hyper variable regions HV1 and HV2 - because they are noncoding, they are free to accumulate mutations without affecting the viability of the cell)

How is an examination quality photograph of a footprint taken?

by placing a ruler next to the footprint when taking the picture. this allows for enlargement to real size. The size of the shoe can give us a rough idea of the height of the person.

Fingerprints used to be collected on _, but the current method is to_fingerprints which can be uploaded to a database for analysis.

cards scan

female part of flower

carpal - made up of stigma where pollen sticks to, style, and ovary (contains the ovule, which will become the seed)

Identifying factors of teeth include:

cavities, tooth pattern, general dental health neglect

extraction process used for very small samples

chelex beads chelex binds metal ions, inactivating nucleases, which protects the DNA & allows extraction

DNA can be isolated from a variety of biological materials. The source of DNA is irrelevant, as long as we can generate a DNA profile. Some people have cells of 2 different types, which would generate 2 different DNA profiles. These people are called _

chimeras - relatively rare, but they must be beared in mind when considering forensics

What type of cases are tried before the state courts?

civil (marriage, divorce, family law) criminal traffic

What is involved in a familial search?

compare DNA profiles & prioritize them in terms of closeness to the match. Parents & children will share 1 allele for each marker. 10 markers examined, there will be 1024 possible combinations for shared alleles. Unrelated individuals will share on average 6 alleles, while siblings will share 13-14 alleles. In each case, there's a wide distribution around the average. By looking at the probability of how many alleles will be identical in unrelated vs related individuals, it may help us narrow down who committed the crime.

dense bone which forms outer surface of all bones, a stronger bone

cortical bone - primarily found in shaft of long bone about 20% of adult skeletal structure`

when can DNA contamination occur?

crime scene transport individuals in laboratory

minutiae point where one ridge crosses over another, making a characteristic X shape

crossover

stimulate osteoclastic activity

cytokines -

DNA can be stored on _, which can provide info on international/national levels

databases These vary from suspect databases, crime scene databases, etc to allow for easy search

stage of death involving breakdown of the tissues and organs

decomposition

As you increase the # of STR regions you look at within the Y DNA kit (depending on the kit you are using), the # of haplotypes(# of individuals present) _

decreases This is because most researchers are using the minimum # of Y STR regions (9). If you stick to this minimum #, you have a much larger comparison population (the less matches you will generate)

form a small triangle

delta

the area of the pattern where there is a triangulation or a dividing of the ridges.

delta (small triangle) A "loop" must have a single delta & a ridge that enters & leaves on the same side

Loops must have one _ and one or more_ that enter and leave on the same side. These patterns are named for their positions related to the _and _bones.

delta/ ridges can either be a radial loop (opening of loops is toward the thumb) or an ulna loop, depending on the direction of the ridges (opening of loop is toward the little finger)

The main method used for determining age of a child's skeleton?

dental development It is a reliable method bc Teeth erupt at specific developmental stages.Age determined through Examination of teeth present & Comparing to development chart. Possible to estimate age into early adulthood.

When the corpse is completely dry (1-3 yrs), what insect will be found there

dermestid beetles

When the corpse's fats are rancid (3-6 mos), what insect will be found?

dermestid beetles

responsibilities of first responding officer

determine if crime scene is safe (is crime still in progress? if so, they must resolve it by taking perp into custody) initial scene assessment to see if it's safe & if anyone needs medical attention (must keep witnesses alive!) identify eye witnesses - separate them from the scene & from each other try to obtain statements as quickly as possible while memories are fresh call for assistance (will vary depending on complexity of scene) restrict access to scene (to prevent contamination as well as to reduce accusations of tampering with evidence - may involve sealing off front door & having officer stand guard to monitor those entering/exiting) log of action (time table of all actions which occur after 1st officer arrives on scene; can be important in court when questioned about when officers arrived on scene, experts present on scene, can prove scene was restricted & evidence wasn't tampered with)

Once mtDNA is extracted, what is involved in the PCR used to amplify it?

different fluorescent tags on nucleotides which are added to amplify the sequence - there is a different colored tag for each nucleotide The detector on genetic analyzer will recognize the tags and will produce a graph of each colored peak via chromatography The nucleotide sequence can then be compared to the reference sequence

Although it may be obvious, any death must be confirmed by a trained professional - usually a_

doctor, coroner or medical examiner Must meet the criteria of death - then pronounced dead. Body can then be moved, handled and processed if necessary ^The place the body was found is treated as a crime scene until proven otherwise

What makes a bone an "irregular" bone?

don't fall into any other category, typically due to their irregular shape

made up of 2 loop patterns in combination, often taking on an S shape

double-looped whorl

Fingerprints can be deposited how?

due to natural secretions of the ecrine gland, present within the friction ridge of the skin the secretions are primarily water. each ridge is dotted with pores, any of which secretions can come. a secretion occurs when we touch anything by pressing our fingers into ink, the ink transferred onto the peaks of the ridges can make an impression if pressed onto paper

How are fingerprints recorded?

dusting will enhance the print, which can then be lifted with some kind of tape it is important to prioritize fingerprinting, as DNA may be extracted from a single cell - thus can be extracted from a fingerprint

How is evidence packaged & labelled?

each article is stored separately to avoid cross-contamination each item must be stored using evidence bags & tags maintain chain of custody by recording who collected evidence, where it was collected, when collected, and offense it is related to

how must wet clothing be packaged?

either dried first, or stored in a plastic bag kept in a freezer to prevent mold growth - mold would damage the evidence

DNA can be collected from _&_ Can confirm identification

enamel and tooth pulp ex: Missing 8 year old boy Remains of a jaw, rib and vertebrae were found Dental examination matched dental record Nuclear DNA results from teeth were inconclusive Mitochondrial DNA results confirmed the relationship between the skeletal remains and the missing boys mother. This confirmed the identification of the remains.

Membrane covering internal surfaces, including the trabecular bone

endosteum Cortical endosteum Trabecular endosteum Osteonal endosteum ^refer to areas where inner membrane is located

what is probable cause?

enough evidence where a typical person looking at it would agree that the person they're trying to arrest is guilty of the crime

Wear on the teeth associated with Acidic wear, such as that resulting from Vomiting or disease

erosion

a procedure that doesn't involve powders, that is used to develop latent fingerprints on a variety of objects.

ethyl cyanoacrylate fuming method (often called the superglue method) - can only be used on non-porous surfaces cyanoacrylate polymerizes the fingerprint to the surface it's on by polymerizing the oils from the fingerprint. it creates a print that can be lifted several times. after placing the object in a chamber with the ethyl cyanoacrylate fumes, black powder is applied to the object so that the print(s) can be lifted with tape. The tape is then adhered to a fingerprint card which can be analyzed.

advantages of extraction kits

everything you need for extraction is in the kit reduced risk of contamination

what is hearsay evidence?

evidence which has been heard from a different or indirect source - it is inherently unreliable, as people do not always tell the truth about what has been heard

advantages of chelex extraction

fast cost-effective no hazardous materials can be carried out in a single tube

If a skeleton exhibits Subpubic concavity is it M or F?

female - males have no subpubic concavity

an impression of the friction ridges found on fingers - why did they evolve?

fingerprints evolved in primates to help with gripping surfaces, provides greater concentration of nerve endings & enhances sensory feeling of touch. Furrows separate the ridges. Complex patterns are formed which remained unchanged throughout one's lifetime. Our fingerprints are very similar to chimps'

Example, cranial bones and scapula Thin cortical bone surfaces with trabecular filled middles

flat bones

breed in dead animals, dung, or decaying material. They skip the larval stage and deposit living first instar larvae.

flesh flies Normally the larvae is found in the open wounds of mammals; hence their common name.

to help find latent prints on multi-colored or dark surfaces.

fluorescent and phophorescent powder and UV lights

STR profile frequency within a population =

frequency of each allele combination for each STR multiplied together

When measuring internal body temperature, which helps determine time of death, where is the temperature taken?

from the liver As decomp occurs, the internal body temp tends to rise again. Taking temp from the liver gives us a consistent site for temp measurement.

Beetle larvae pupate, and from this pupa emerges a _

fully formed, sexually mature adult beetle. Adults have an extremely variable lifespan, from weeks to years, depending on the species.

1st step in quantifying DNA present in a sample

gel electrophoresis

_ are combined to form a Y haplotype for a sample

genetic variation at multiple points

set of SNPs (single nucleotide polymorphisms - aka mutations) on a single sequence that are statistically associated

haplotype made up of the mutations identified via mtDNA sequence; set of nucleotide changes inherited from one generation to the next

sequence variety: more than 1 nucleotide base appears at a single site within a mtDNA sequence

heteroplasmy

Makes up 70% of dry weight of bone

hydroxyapatite includes calcium phosphate, calcium fluoride, etc present in crystalline and non-crystalline forms

A forensic entomologist does what?

identifies the immature insects & their size/development calculates the growth of the insects & passage through stages of the life cycle in laboratory compares the growth against weather conditions to estimate time of oviposition

What happens when a crime is committed?

if a crime is witnessed by a police officer, you can go straight to arresting the person & taking them to jail. otherwise, the crime must first be reported or discovered (911 call or call to police dept). police arrive to scene & begin investigation, interview witnesses, secure crime scene, begin investigating scene & processing it by tagging/bagging/collecting evidence. A suspect may be brought in for questioning.

the first mitochondrial haplotype was identified where?

in Africa - "L" (at this time there was only 1 haplotype, that we still see in people today) the first subtype of this haplotype was L1, which was found to have migrated from original location and spread around Africa. This is how we can study migration within a continent. There are now many haplotypes present all over the world

how must evidence contaminated by hydrocarbon fuel (such as petroleum/gas) be packaged?

in a nylon bag tied with a special knot which creates an airtight seal

How must small evidence (such as hairs/fibers) be packaged?

in a sealed envelope, then put in a larger evidence bag

A cadaver is a very rich but ephemeral (short-lived) resource There is tremendous competition among organisms, especially in the early stages of decomposition. Insect colonization of a corpse occurs how?

in a series of stages. Different groups are adapted to different stages of decomposition. Thus, there is a fairly predictable sequence of colonization

How is chloroplast DNA packaged?

in a single circular chromosome, similar to mtDNA The genes present in chloroplast DNA, represent all the ingredients needed for chloroplasts to carry out transcription and translation of their own genes, which gives them full control of producing their own proteins.

How are fingerprints classified?

in a three-way process: by the shapes and contours of individual patterns, by noting the finger positions of the pattern types, by relative size, determined by counting the ridges in loops and by tracing the ridges in whorls.

In what cases would osteoporosis be a good identifying feature?

in males and young people (under 55)- since it is most common in older females *kyphosis is a common symptom of osteoporosis*, which is forward bending of the spine

first time "DNA fingerprint" was generated

in the 1980s by Dr. Alec Jeffries used restriction enzymes to cut different DNA samples to see which RFLPs matched the blood found at the scene

Difference between US & UK DNA profiling

in the UK, 10 STR regions & one gender marker in the US, 13 STR regions & one gender marker are examined *The probability of matching 2 unrelated people in the UK is statistically 1 in a billion. The probability in the US is 1 in 1.5billion due to the 3 additional STR regions examined. The UK profiling system began earlier than that in the US. At the time, the kit available looked at 10 STR regions. If the UK increased the # to 13 STR regions, their current profiles may no longer be forensically useful

where is the DNA after the sample is centrifuged?

in the liquid (upper aqueous phase)

- pill bugs, spiders, mites, centipedes that use the corpse as an extension of their normal habitat

incidentals

In addition to haplotypes, what can we use to study mtDNA?

individual point mutations (aka SNPs) they can occur throughout the genome, not just in the hyper variable regions we look at SNPs to identify which haplotype the person is of

the most diverse and abundant forms of life on earth.

insects There are over a million described species- more than 2/3 of all known organisms There is more total biomass of insects than of humans.

Scientists are unlikely to disagree on the facts, but they typically disagree on _

interpretation - as they are working under different assumptions Responsibility of the scientist is to search for verifiable scientific facts and provide impartial evidence in court Independent experts ensure an equality of arms Appropriate lab technology should be available to both sides

lamellae between osteons

interstitial lamellae

Which search patterns are best to use when only a single officer is present?

inward-spiral (begin at perimeter & make smaller & smaller inward spirals toward center of scene) outward-spiral (start at center - maybe where victim's body is present - and make spiral patterns outward toward perimeter)

Serious crimes, which require as much evidence as can possibly be recovered, may utilize what search patterns?

inward-spiral pattern outward-spiral pattern zone pattern parallel pattern grid pattern

Majority of this type of bone is trabecular Thin cortical bone wall

irregular bone

ethical questions regarding familial searching

is the use of familial searching to be an unwarranted invasion of family privacy? Certain groups such as some ethnic minorities and young males are disproportionately represented on forensic databases. Is this potential for bias within the database acceptable in law enforcement? Should volunteers (such as victims, witnesses, mass screen volunteers) be able to withdraw their consent at a later stage? Would the collection of DNA from everyone at birth be more equitable than collecting samples from only those who come into contact with the criminal justice system? Would the establishment of such a population-wide forensic database be proportionate to the needs of law enforcement?

very short fragments

island - look like islands in a sea of other ridges

problems with RFLP profiling

it can require a lot of genetic material to generate a DNA profile - the technique could use all the material that you have, which would eliminate the possibility of re-testing the material later on. If you have only trace amounts of genetic material, this method is not optimal

How is mtDNA inherited?

it is inherited from the mother There is 1000 mitochondria in sperm but up to 1million in egg Eventually the sperm is diluted out, thus any mutations are from the mother

Compare the teeth from the crime scene with_. This is useful in cases involving children. As the teeth are _, it is less useful for determining the age in adults.

known teeth development charts fully developed by the late teens

one of the few mammals other than primates which has fingerprints

koalas - very similar to humans' & chimps' fingerprints

Stature (height) obtained from measuring length of _ Various calculations depending on _,_&_

long bones Bone, Gender, Ethnicity

4 main types of bones

long bones (including humerus, femur, tibia, metacarpals & phalanges) short bones (carpals, tarsals in wrists/feet) flat bones (scapula, should blade, sternum, cranium) irregular bones (vertebrae & mandible)

What features must a bone have to be classified as a "long" bone?

longer than it is wide & normally they have growing plates/epiphyses at the ends of them. the bone must be compact with a spongy bone center which contains the bone marrow

what is the role of forensic anthropology at a burial crime scene? ( decomposed/burned/mummified body )

looking at the skeleton & remains in order to determine age, gender & ID of body ^they typically work with unrecognizable skeletons Their knowledge of the human skeleton complements the forensic pathologist's knowledge of soft tissue

_can also be used to reveal latent prints. This type of powder works better on shiny surfaces or plastic containers.

magnetic powder

Morphological analysis via light microscopy allows what?

magnification specimens up to 60 times

What is a felony & what are examples?

major crime punishable by fine and/or more than 1 yr in prison. convicted in court and require additional steps. can result in 5 yrs to life in person, the death penalty, fines up to $100k ex: arson, aggravated assault, burglary, robbery, homicide & rape

Supra-orbital ridge More pronounced in_than in _

males than in females

Most coroners or medical examiners require positive identification, which requires what?

match of DNA, fingerprints, dental records, x-rays, or unique apparatus, such as an artificial joint.

likelihood that 2 unrelated people selected at random have the same DNA profile

match probability

mtDNA can be used to identify geographic locations of _ & relationship between _

maternal ancestry maternal relationships between 2 individuals (maternity cases, immigration cases, identifying remains)

A dead body found at a crime scene is handled and processed by the_ Officers and CSIs cannot touch or move the body until _ Any evidence on a body is collected by the ME staff and turned over to _

medical examiner's office. the ME has given permission to do so. the crime lab.

best known method of detection, involves a current & a magnetic field. The receptor converts what it receives to a sound which it emits

metal detectors useful for detecting bodies where metal objects are present (metal pins/plates, jewelry, dental fillings, or stolen goods if you're not looking for a body)

Insects undergo either incomplete or complete _ Larva have a soft tubular body and look like worms. Fly species larvae are "_".

metamorphosis (Egg to larva to pupa to insect) maggots

The ADH gives a minimum_ Need to think about other factors as well, such as :

minimum time since death Weather conditions Exposure to the environment Location

What is a misdemeanor & what are examples of such crimes?

minor crimes punishable by fine or jail time. require court appearance & trial. max of 1 yr in jail. fines from $250-$2500 ex: minor assault/battery, possession of small amount of illegal drugs, theft, first offenses of drunk driving, vandalism, shoplifting,trespassing or prostitution

What is an infraction & what are examples of such crimes?

minor offense/petty crime, penalty is usually a fine. ticketing officer issues a ticket and once you pay it, it's over ex: jay-walking, minor traffic offenses, littering

In addition to the nucleus of the cell, DNA can also be found in the cytoplasm in organelles called _

mitochondria - these help to produce energy within the cell. The # of mitochondria present in a cell depends on the type of cell (the greater the energy requirement of the cell, the more mitochondria)

Evidence of endosymbiosis

mitochondria have prokaryotic characteristics (circular DNA, genetic code characteristics) discovery of a single proteobacterial cell from which all mitochondria originated would solidify this theory

mtDNA has been used to trace back many generations, including _

mitochondrial "Eve" & to trace migrations through Africa, and throughout the world can be done by looking at mtDNA haplotypes

How are family reference samples used to identify a body?

mitochondrial DNA (maternally inherited) autosomal STR profiling *test used depends on age/condition of remains. STR profiling is preferred is body is fresh. mtDNA is used if the body is not fresh

forensic analysis which has a relatively low discrimination, due to the fact that this portion of the DNA is passed down thru the maternal line

mitochondrial DNA (mtDNA) - can be useful but not routinely done because STR analysis is a much faster way to generate DNA profiles

most mtDNA mutations occur where?

most mutations occur in the D-loop (within it are the hyper variable regions HV1 and HV2 - because they are noncoding, they are free to accumulate mutations without affecting the viability of the cell)

Other uses of forensic entomology include what?

movement of the corpse manner and cause of death association of suspects with the death scene detection of toxins, drugs, or even the DNA of the victim through analysis of insect larvae.

If you were to find remains which are many years old, what do you think is the most suitable DNA test to perform for ID purposes & why?

mtDNA analysis is optimal for identifying very old remains. The mitochondrial genome is present much longer than the nuclear genome due to 2 reasons: there are many more copies of the mitochondrial genome in comparison to the nuclear genome & the spherical shape of the mitochondrial genome inhibits degradation by exonucleases

MtDNA analysis is of value to evolutionary research & forensic science. Describe how mtDNA can be examined for evolutionary research & how this might help in forensic casework

mtDNA can be examined in order to determine locations of maternal ancestral origin. This is done by the generation of haplotypes & tracing those haplotypes around the world. This may be useful in forensic research when identifying a body. By taking a reference sample from a maternal relative, it can be determined whether the victim is related to that person or not.

what might cause a greenish appearance on the abdomen?

multiplication of digestive microbes, causing decomposition to take place

What is required to make an arrest?

must have probable cause. The FBI, DEA and other agencies involved with evidence processing may get involved to build evidence against suspect. Once enough evidence is collected for probable cause, they can go to the court to have an arrest warrant issued by the judge. The police serve the warrant & arrest the suspect in question. At the police station, the suspect goes through booking & is interrogated,interviewed, or put in a line up. Once arrested, the person must be arraigned. The route at this point depends on the type of crime being pursued. Charges could also be dropped or dismissed at this point.

disadvantages of chelex extraction

not very effective for RFLP typing, because chelex denatures ds DNA - it can only be followed by PCR, but it does not denature all inhibitors of PCR

recording the crime scene the way it was found includes what?

notes, photos (note location of photo, who took it, direction camera was pointing, date/time image was capture & lighting conditions), video, sketches (useful for pathology to see how victim was found & to see if pieces of evidence were removed)

What is involved in the injury inspection?

noting previous injuries and those which might have been sustained during an attack

Differences between nuclear DNA & mtDNA

nuclear DNA has far more base pairs 2 copies of nucDNA per cell (1 allele from each parent) can have >1000 copies of mtDNA nucDNA is packaged linearly in chromosomes while mtDNA is circular nucDNA is inherited from the father & mother while mtDNA is inherited only from the mother nucDNA undergoes generational recombination while mtDNA does not nucDNA is unique to the individual (except identical twins)while mtDNA is not nucDNA has a slow mutation rate; mtDNA's is faster nucDNA was sequenced recently;mtDNA was sequenced much earlier due to smaller # of nucleotides

DNA is found in the _ of the cell in the form of _.

nucleus chromosomes

What is the mitochondrial origin?

of bacterial origin - endosymbiotic theory mitochondria were once a primitive bacterial cell. larger eukaryotic cells ingested these bacteria & began to depend on each other for survival, generating a permanent relationship

What are the 2 DNA separation mechanisms?

ogston sieving & reptation

The amelogenin gene is present on which chromosomes?

on both the X and Y chromosomes - it is a different size on the X and Y

For every three molecules of CO2 that enter the Calvin cycle, the net output is _. For each G3P synthesized, the cycle spends _ molecules of ATP and _molecules of NADPH2. The light reactions sustain the Calvin cycle by _

one molecule of glyceraldehyde 3-phosphate (G3P) nine molecules of ATP and six molecules of NADPH2 regenerating the ATP and NADPH2

Types of DNA extraction

organic extraction (using phenol chloroform) chelex beads DNA extraction kit

Bone resorption is the process by which....

osteoclasts break down bone and release the minerals, resulting in a transfer of calcium from bone fluid to the blood. The osteoclasts are multi-nucleated cells that contain numerous mitochondria and lysosomes.

bony projections that form along joint margin

osteophytes ("bone spurs") They form because of the increase in a damaged joint's surface area. This is most common from the onset of arthritis. Osteophytes usually limit joint movement and typically cause pain.

disorder in which there is an absolute decrease in bone mass- the bones become brittle & more likely to fracture

osteoporosis (rate of absorption is greater than that of bone formation, resulting in reduction in bone density. the most common bone disease - most women over 55 will have a fracture in their hip or elsewhere. calcium needed for bone strength is being deposited elsewhere. )

If it weren't for decomposition of all living things, what would happen?

our world would fill up with dead bodies. When an animal dies, female insects will be attracted to the body. They enter exposed orifices or wounds and lay eggs or larvae.

lamellae around circumference of bone

outer circumferential lamellae

how must dry clothing/shoes be stored?

paper bag

What search patterns are best to use when the crime scene is large, such as a field?

parallel pattern (multiple officers line up & walk in parallel across crime scene) grid pattern (2 parallel searches, each occurring in different directions)

Drops created or formed by the force of gravity acting alone

passive bloodstain (drops, drips, pools, clots)

Membrane covering the majority of outer surfaces

periosteum (critical in infants to bone formation)

liquid-liquid DNA extraction

phenol chloroform - used also for protein extraction involves breaking down cell to expose DNA (SDS+proteinase K), then equal volumes of phenol & chloroform are used to burst the cell, then centrifugation is used to separate organic phase from upper aqueous phase - DNA will migrate to upper aqueous phase, which can be transferred to a new tube & exposed to alcohol for alcohol precipitation, then more alcohol is used to purify the DNA

How is blood spatter evidence recorded?

photo of spatter examine pattern at the scene or take it to the lab (if spatter is on something such as a t-shirt or piece of furniture) blood spatter expert will interpret pattern genetics expert may take sample of blood for DNA analysis - only after interpretation is complete so as to not disrupt the pattern

what is the procedure for dealing with fingerprints?

photograph fingerprint FIRST then decide whether to dust or swab - swabbing the fingerprint for DNA evidence will essentially destroy it

As soon as they are exposed, any body parts or bones should be_ . All sediment from grave should be _.

photographed (each bone should be photographed) screened to search for hair, bones, teeth, fragments or other evidentiary material Routine photographs of scene should be taken periodically throughout process.

Arch in which Ridges enter on one side and exit on the other side.

plain arch

Touch soft substance such as putty, soap, paint, etc. actual impression of ridges.

plastic prints

Most DNA differences are _

point mutations

carries the male gametes of flowering and cone-bearing plants

pollen

minutiae point which lines the ridge, where oil & sweat are secreted

pores/cores (may not be present in all fingerprints)

If it's a misdemeanor, what happens after arraignment?

pretrial arraignment - person is officially charged with crime. Then they go to trial where evidence may be presented to jury. If guilty, they move to the sentencing hearing. The person then ends up in jail, probation, or gets fines

Location and determination of trace evidence is critical. Differentiation of_&_ disturbances within a grave is necessary to correctly reconstruct the process of body placement . Maintaining a chain of custody is critical.

primary and secondary disturbances This is important because it can link the crime scene to the perpetrator.

Looking at the condition of remains includes what?

primary postmortem processes Decomposition stage Evidence of scavenger modification (scavengers & insects are attracted by the smell, especially if the body is near the surface or not wrapped up) Insect life cycle (insects may lay their eggs in the remains as a food source. looking at insects present and their stage of life can tell us when the burial occurred & the rate of decomp) Weathering (has the body been buried for some time or exposed to sunlight, evidence of erosion of soil around or near body) Modification by water, sand or geology (all of these affect decomp rate)

How does PCR work?

primers are developed based on the DNA sequences close to the region of interest. 2 primers are designed: 1 will bind to each end of the region of interest. 1 primer will bind to region where DNA nucleotides are complementary & will add free nucleotides in a 5' to 3' direction. The primer on the other end will add nucleotides in the 3' to 5' direction. The primers may have tags for identification during sequencing. The PCR reaction is performed in a temperature controlled environment, which controls the rate of replication.

According to The Times (2007), generally there is a 52% chance of an immediate match between a crime scene sample & a personal profile on the national database when _

profiles from new unsolved crime scenes are added -there is a good chance that the person who committed the crime is already on the database

Preserving the crime scene includes taking what precautions?

protective white suits closing body bags shoe covers gloves masks metal platforms laid out/common approach pathway *volume crimes such as burglaries do not require as much contamination prevention restrict access to scene, monitor who comes & goes and when

stage of death involving breakdown of tissues and the liquefaction of organs

putrefaction

Comprehensive _ are in operation in forensic laboratories,due to the impact that scientific evidence can have on a case and on the suspect; it is important to have these procedures in place.

quality management schemes Test procedures must be reliable and accurate Can use published procedures which have been subject to peer review On some occasions a scientist may have to design a new procedure - this will only be accepted if there is not already an accepted test available Decisions should be discussed with colleagues Interpretation of results should also be discussed

what does the national DNA database allow for?

quick identification of offenders make earlier arrests secure more convictions provide critical investigative leads

It's best to identify what kind of diseases in IDing?

rare diseases will reduce the suspect pool much moreso than common disease

If anthropologist has participated in recovery, he or she will document _

recovery processes and forensic taphonomy of site.

biological samples provided by family for comparison

reference samples (typically in the form of blood or buccal swabs)

What are pollen & spores?

reproductive systems of flowering plants, ferns, mosses etc. When bees feed on flowers, the pollen is transferred to the bee, which it carries to the next flower and transfers the pollen to that flower (insect pollination).

minutiae point where ridge endings exist

ridge ending

A fingerprint is made of a series of _ and _on the surface of the finger. The uniqueness of a fingerprint can be determined by the_of ridges and valleys as well as the location, shape, and position of _, which are points where the ridge structure changes.

ridges & valleys pattern minutiae points:points where the ridge structure changes

Pollen is produced by what kind of plants?

seed plants: Gymnosperms (Coniferophyta and Ginkgophyta) Have naked seeds not enclosed in ovaries. Usually cones. Angiosperms (flowering plants) Seeds contained in fruits, i.e. mature ovaries.

How does RAPD differ from PCR?

segments of DNA are randomly amplified. In a normal PCR amplification primers are designed which are specific to the sequences flanking the sequence of interest. The PCR leads to the amplification of a specific segment of DNA. In RAPD analysis, the target sequence which is to be amplified is unknown. The primer is designed with a arbitrary sequence.

term used to denote a genetically inherited characteristic that confers no benefit or harm to the individuals ability to successfully reproduce

selective neutrality

General life cycle of beetles: A single female may lay from _-_ during her lifetime. The larval period varies between species but can be as long as _.

several dozen to several thousand eggs several years

CODIS was originally established for DNA of _ but has since expanded to include many crimes of a serious nature. The difference between the US CODIS system & the UK's database is _

sex offenders In the US, only those CONVICTED of a serious crime will have their DNA listed as an offender profile

Supra-orbital margin Female - _ Male _

sharp / rounded

trauma caused by a sharp object such as an axe, sword or knife

sharp force trauma

how are footprint/shoeprint evidence recorded?

shoeprints aren't unique to a person, but might be helpful if compared to the suspect's sole - which can reduce # of suspects

PCR is the amplification of _ sections of DNA

short It mimics DNA replication which occurs during normal cell division. Only the regions of interest are replicated - we can generate millions of copies of the regions of interest in just a few hours

short repeats of DNA nucleotides which occur one after the other

short tandem repeats (STR) ex: GCC-GCC-GCC-GCC If there are the same numbers of repeats on both chromosomes, they are homozygous. If there is a different number, they are heterozygous.

Shadows seen from aerial photography can indicate what?

sign of a burial present, or a burial collapse. As the body decomposes, it causes the layers of dirt to shirt which can result in a collapse

method used for Y chromosome analysis

similar to STR technique used for autosomal DNA profile With Y DNA profiling, we are looking only at the single Y chromosome. 17 STR regions are examined and make up the Y DNA profile

crime scenes include what?

site of offense victim suspect homes of witnesses, victims & suspects *all crime scenes must be processed in the same manner

The _ of a database is important in determining the presence of haplotypes

size (the bigger the database, the better the statistics for a random match probability calculation)

The rate of migration of DNA within agarose gel is primarily based on what factor?

size of the DNA fragments

Why might it not be possible to analyze all 13 STRs?

small amount of DNA recovered from scene DNA is degraded DNA mixed (suspect+victim, multiple victims) If the full profile can't be examined, the statistical weight attached to the match is lower & possibility of coincidence higher

More significant pollen will fall from a small plant or tall tree?

small plant

how much DNA is required for extraction?

smaller and smaller amounts are required: single cells (tho these processes are still being debated) & droplets of blood are used - which are then exposed to PCR

After taphonomic documentation is complete, _ may be done.

soft tissue examination Fingerprints examined for viability. (compared to database) Internal tissues and organs. (can determine if it was an accidental death or a crime has taken place, can tell us about the weapon used) Bone formation in child victims. (or bone breakage which could have led to death or aid in identification) Screening for small bones or artifacts. X-ray materials.

the asexual reproductive bodies of ferns, mosses, and fungi

spores Plants produce vast quantities of microscopic pollen and spores which they disperse with the help of animals, wind, or water. Although we can't see individual pollen grains with the naked eye, they occur on almost every surface in nature.

male part of flower

stamen (anther & filament)

What makes a bone a "flat" bone?

strong flat plates which provide protection for organs and act as a base for muscle attachment

What does forensic palynology refer to?

study of pollen/spore evidence in legal cases also includes legal info derived from microorganisms in addition to pollen & spores - can be found in freshwater/marine environments

How is drug evidence recorded?

substance must be identified via a "presumptive" test on the scene - after which it must be sent to a lab to confirm whether substance is illegal

A "hit" from a database can mean what?

suspect to scene match scene to scene match suspect to suspect match(person has given different ID details on different occasions)

study of postmortem changes in the body due to environment.

taphonomy Changes to the body may include normal decomposition, movement or modification by flowing water, freezing, mummification or alteration or scattering of body parts by scavengers. The rate of decay will speed up with a high temp, but slow down with lower temps. Bodies in water tend to decompose more slowly.`

Hardest part of body attached to jaws

teeth: serves to help digest food, act as a defense mechanism, etc. teeth are made of a crown with enamel surrounding a pulp.

What environmental factors affect estimation of PMI?

temperature, rain/water, exposure & location

Arch in which has a spike in the center.

tented arch

mtDNA genomes can exhibit more than one nucleotide at a time due to _

the # of genomes found within the cell, some with mutations and others with none. this will make it appear that more than 1 nucleotide exists at a single location within the mitochondrial sequence (heteroplasmy)

What is Forensic odontology ?

the application of dentistry in legal proceedings deriving from ANY evidence that pertains to teeth.

What is photolysis?

the decomposition or separation of molecules by the action of light, as occurs in the light reaction taking place in the grans (stacks of thylakoids within chloroplasts)

Friction ridge pattern forms in_.The friction ridge arrangement is determined by _.

the fetus about 28 wks after conception dermal papillae - layer of cells which separates epidermis from dermis If you damage the outer layer of skin without damaging the dermal papillae, it will not alter the friction ridge pattern (fingerprint). If you have a deeper cut/wound which damages the epidermis, dermal papillae & dermis, the friction ridge pattern will be permanently altered due to scar tissue. (this will only affect the part of the print that was damaged)

Most countries use fingerprint analysis & store fingerprints on a database, classified by _

the main feature present on the center of the print

DNA has a negative charge due to what? This causes them to migrate toward which electrode in electrophoresis?

the phosphate group they migrate toward the anode - the positive charge

How is mtDNA useful in identifying remains?

the remains' DNA can be compared to that of a maternal relative

What is "base temp" when calculating ADH?

the temp below which the insect in unable to develop

What are chloroplasts?

the typical organelles of green plants. These organelles contain the plant cell's chlorophyll responsible for the plant's green colour and the ability to absorb energy from sunlight. This energy is used to convert water plus atmospheric carbon dioxide into sugars by the biochemical process of photosynthesis.

Permanent adult teeth come in when primary teeth fall out; they are permanent because _. _ come in around the mid teenage years.

they establish roots inside the gums Third molar

What are fungal spores?

those associated with fungi, which have the sporopollenin structure as well. They can be useful at crime scenes because they can be found in rotting vegetation. We may find fungi at burials/crime scenes. By looking at the type of spores present, we can determine if the person had more than one burial site and also use it to link suspects to the scene. Fungal spores are asexual and immotile.

Inside the chloroplasts are stacks of discs called _, and they act to trap the energy from sunlight. These stacks are called _. They are connected with an extensive system of tubules.

thylakoids/grana The thylakoid membranes contain chlorophyll and other pigments arranged in antenna arrays to capture light energy. The process of photosynthesis consists of two sets of chemical reactions called the light reaction and the dark reaction. The light reaction takes place in the grana. The dark reaction takes place in the stroma.

Forensic entomology is primarily used to determine what?

time since death (the time between death and corpse discovery) This is called postmortem interval or PMI.

disadvantages of extraction kits

time-consuming difficult to run large #s of samples (due to so many washing steps) labs can't create their own solutions

disadvantages of phenol chloroform extraction

time-consuming hazardous materials required requires multiple transfers of DNA from tube to tube (increases chance of contamination or mixing up tubes)

what is the purpose of performing PCR (polymerase chain reaction)?

to amplify the amount of DNA to move it from a trace level to generating enough copies to successfully create a DNA profile

why are controls used?

to ensure that we can rely on results produced from forensic samples

What else can mtDNA be used for?

to identify geographic regions of ancestry/origin

A new test has been proposed in the UK for what purpose?

to scrutinise an expert witnesses evidence, this has been proposed to make trials more fair. Judges will be able to hear and test expert evidence before a jury is sworn in under new plans drawn up by the Law Commission. The test is aimed to ensure experts are 'reliable and trustworthy' As a result, judges in England and Wales would be able to exclude evidence from experts such as scientists and doctors.

Principle route of infection - respiratory tract Can spread to other organs via blood Including skeletal system

tuberculosis, Caused by Mycobacterium tuberculosis, can spread into and affect bone Very contagious, mainly affect lungs. Once it enter lungs it can then enter the blood and spread to other organs such as skeletal system

method of search/recovery of physical evidence depends on what?

type of crime (volume vs. serious) collecting evidence from volume crimes typically includes high quality evidence in areas that have been clearly disturbed (along route perp has taken thru crime scene such as entry, exit, areas where items were stolen). In volume crimes you are mostly looking for fingerprints & DNA samples - not a lot of evidence, just enough to identify perp

pattern of search depends on what?

type of crime, size of crime scene, # of people present at scene & what evidence you're expecting to find

Arguments against a universal DNA database

unnecessary expense, as most people do not participate in crime DNA can reveal personal information, which could be used by the government & police ethically, is it ok to take DNA without consent? would create a nation of potential suspects DNA evidence is not always relevant (i.e fraud & online crime)

When the corpse undergoes ammonia fermentation (4-8 mos), what insect will be found there?

various flies & beetles

All bones form through ossification of one or more centers Earliest bones to fuse:

vertebrae occipital

3 different types/forms of fingerprints

visible prints, plastic prints, & latent prints Locating visible or plastic prints at the crime scene normally presents little problem to the investigator, because these prints are usually distinct and visible to the eye.

There are separate UK databases for what?

voluntary databases (profiles should be removed once investigation is complete) missing persons database

may be necessary in cases of muddy conditions.

water screening water can be used to wash off the bones - the water can be screened as well to ensure we're not missing any evidence

Blood drops landing at angles less than 40 degree often produce secondary stains called _

wave cast-off

on the sole, unique to each shoe & dependent on how a person walks - and how long they have worn the shoe

wear pattern

Similar to other methods of adult age estimation, sternal rib ends are used by assessing the degree of morphological change where what happens?

where rib attaches to sternum-Ideally use 4th rib Essential points: Young individuals have marked billowing, changes from a U-shaped pit, to V-shaped pit, widening pit, new bone growth on edges

Human fingerprint patterns fall into three main groups:

whorls, loops, and arches.

Accounts for 35% of all fingerprint patterns, have at least one ridge that makes a complete circuit. They also have at least two deltas.

whorls: plain, central pocket, double-looped and accidental

advantages of phenol chloroform extraction

works well for recovery of high molecular weight DNA good for extraction from tissues (muscle, liver etc)

Arguments for a universal database (DNA collected from everyone at birth)

would overcome any race, gender, socioeconomic, etc biases would remove stigma associated with being placed on a police database would deter people from committing crimes crimes would be solved much faster more cold cases would be solved

Can 2 people have the same DNA profile?

yes, identical twins/triplets can siblings (blood relatives) are much more likely to share similar DNA profiles than unrelated individuals - similar PARTS are expected, rather than identical DNA profiles. the chances of 2 siblings having identical profiles is one in a million or 1 in a billion

What search pattern is best to use when more than 1 officer is present?

zone pattern (scene is divided into zones & each zone examined by an officer)