che 113 exam 2

post-mortem interval

Elapsed time from a death to the discovery of a cadaver. Flies (especially calliphorids and sarcophagids) can be vital in determining the PMI Premises: Flies will begin oviposition as soon as they discover a body, Succession on a corpse is predictable, Insect development is predictable

paint analysis

Lincolnshire, UK - 1991-1993, two murders by axe. nImprint of axe found on sofa and pillows axe found in local pond and paint analysis by ICP-AES matches paint at crime scene axe shape matches patterns found on sofa.

blood

circulatory system and is continually being pumped distributes oxygen and nutrients, removes wastes (exhalation), others to the kidney and liver for processing and elimination mixture of cells and plasma

projected bloodstains

created when a blood source is subjected to an action greater than the force of gravity the size, shape, and number of resulting stains will depend on the amount of force utilized to strike the blood source

postmortem

after death

hair growth

anagen - up to 6 years, length of anagen determines maximum hair length catagen - usually up to several weeks telogen - up to 6 months animals that shed synchronize the telogen phases hair growth fairly uniformly at .5mm/day

crowner

ancient, king's representative for examining deaths

perimortem

at or around the time of death

decomposition

autolysis - normal internal process putrefaction - bacterial decomposition - various stages (fresh, bloated, etc) insects and animal action

automated fingerprint identity system

automated scanning devices integrated automated fingerprint identification system (IAFIS) next generation identification (NGI)

forensic blood analysis

blood id (is it blood?) blood origin (human or other source) blood type blood spatter analysis

projected bloodstain - cast-off stains

blood released or thrown from a blood-soaked object in motion

projected bloodstain - impact spatter

blood stain patterns created when a blood source receives a blow or force resulting in the random dispersion of smaller drops of blood

dripping blood

blood trickles downwards blood drop grows until Wt (G) > S.T. single drop breaks free (teardrop shape) surface tension pulls in vertically and horizontally shape settles into sphere does not break up until impact

specific types of antigens on our red blood cells determine...

blood types (only 27 known)

forward spatter

blood which travels in the same direction as the source of energy or force which caused the spatter

projected bloodstain - arterial spurt/gush

bloodstain pattern from blood spurt under pressure from a cut artery

duties of the medical examiner

document and interpret injuries and diseases collect evidence estimate postmortem interval determine and certify the cause and manner of death authorize cremation (50%) and organ and tissue donation requests testify in court

passive bloodstains

drops created or formed solely by the force of gravity can be subdivided into drops, drip patterns, pools, and clots

natural

due to disease, illness, or pathology

uses of forensic ecology

estimations of postmortem interval (PMI) - time elapsed between the discovery of remains and the actual death of the organism locating human remains and determining whether the remains have been moved (differentiate burial from death sites) determining relationships between people and places (e.g., has a person recently visited a particular site) determining if a crime site has been disturbed (e.g., has something been hidden, removed, changed, or been buried at a given place and when these changes occurred) validating or disproving disputed events (e.g., has a person lain or kneeled on a particular patch of ground or what did someone last eat as determined from plant remains in the stomach) recreating a timeline of events in a crime commission

common types of trauma

firearm injuries drowning/aspyxia blunt force trauma sharp force trauma vehicular trauma fire-related deaths sudden and unexplained deaths

livor mortis (lividity)

gravity causes blood to settle in vessels 1-2 hours color changes in skin pressure changes color early on (blanching) blanching halts 8-12 hours

blood id - is it blood?

hemoglobin has peroxidase-like activity (enzymes that accelerate oxidation of organic compounds)

blood chemistry

hemoglobin is a protein containing heme groups

primary classification

henry (fbi) system - all prints fall into one of 1024 groups pair up fingers o hands determine whorls - list numerical 10 finger system

polyethylene

high density polyethylene (HDPE): staright chain polymer - chains "pack" together tightly like a crystal - high density, high strength, high mp low density polyethylene (LDPE) - branched chain polymer - side groups impede "packing" of the chains - low density, low strength, low mp

how old is it?

historic versus forensically location and context co-burial items condition

5 critical questions for bones

is it bone? is it human bone? how old is it? whose bone is it? how did they die?

AFIS

law enforcement agencies, such as the fbi and the scotland yard, have built up vast collections of fingerprints a fingerprint is first classified and compared with filed prints to try and establish a match, and therefore to identify a possible suspect

benzidine color test

previously used but dropped due to carcinogenic reagents

cuticle

scales on exterior of hair shaft - keratinized

whose bones are they?

sex age stature trauma pathologies hip bone is most useful for adults teeth: erupted or not? epiphyses: fused or unfused?

proxy indicators

small amounts of identifiable material from an ecosystem that can indicate with relatively high accuracy information about the entire ecosystem from which they originated

satellite spatter

small droplets of blood that are distributed around a drop or pool of blood as a result of the blood impacting the target surface

forensic botany

study of plant life: 400,000 known species and biggest (1.3 million lb) and among smallest life-forms (1 mm) uses of forensic botany (1) tracking a suspect's or victim's movements, (2) validating alibis and proposed timelines of events, (3) determining how long someone has been dead, (4) dealing with issues of plant-based poisons and toxicology, 5) deciding on whether a particular wooden tool has been used for a particular purpose, (6) investigating food adulteration cases

osteology

study of skeletal remains - each bone studied individually human bone versus animal bone macroscopic differences - radiology, observation, measurement microscopic differences

forensic pathologist

subspecialty of pathology that deals with death investigations

antigen

substance that can trigger an immune response, resulting in production of an antibody as part of the body's defense against infection and disease

immunoassay

technique utilizing antibodies to bind specifically to targeted substances in a specimen in order to identify their presence

spatter

that blood which has been dispersed as a result of force applied to a source of blood. Patterns produced are often characteristics of the nature of the forces which created them

red blood cell uniqueness

strange shape--- a biconcave disc, round and flat, like a shallow bowl no nucleus, the nucleus is extruded when cell matures change shape without breaking as it squeezes single file through the capillaries contains hemoglobin, a molecule specially designed to hold oxygen and carry it to cells that need it

zoology

study of animal life

entomology

study of insect life

botany

study of pant life

plasma function

liquid portion of the blood containing electrolytes, nutrients, waste products, vitamins, hormones, clotting factors, and proteins such as albumin and immunoglobulins (antibodies to fight infection)

stature

long bones are best measurements and use formula

projected bloodstain - impact types

low velocity - gravitational pull up to 5 feet/sec, relatively large stains 4mm and greater medium velocity - force os 5 to 25 feet/sec, stain size 1mm to 4mm high velocity - force of 100 feet/sec and greater, stain size 1mm and smaller

cause of death

medical diagnosis denoting disease or injury proximate cause of death - initial injury that leads to sequence of events which cause death immediate cause of death - injury/disease that finally kills a person manner of death - intent or seres of events that brought bout the death

hair structures

medulla vary from person to person and even among hairs from one person 3 main medulla types: continuous, interrupted, and fragmented growth phases - anagen: initial phase where hair actively grows - catagen: transition between active and loss stage--- slowed growth - telogen: final phase resulting in hair loss

death examined by medical examiner

no doctor available to sign death certificate violence sudden of unexpected threat to public health prisoner or in a prison suspicious, unusual, or unnatural related to an occupation related to medical procedure (medical misadventure)

red blood cells aka erythrocytes

most abundant cells in the blood gives it characteristic red color 5M RBCs per cubic microliter 40%-45% of the blood blood percentage is measured and called the hematocrit---the ratio of cells in normal blood is 600 RBCs for each white blood cell and 40 platelets

forensic ecology

natural world companions; animals, plants, fungi, protists, bacteria and others studying organisms and their environments and using these relationships to look for observable changes or patterns that can provide unique legal information habitat: climate, non-living components, light conditions

type o

neither protein is present

antigens

on blood cell surface type a - only the a protein is present type b - only the b protein is present type ab - both proteins are present type o - neither protein is present

preserving prints

photography (analog and digital imaging) lifting with tape

liquid blood

physical properties: viscosity, surface tension, specific gravity behaves as a projectile in motion: biology, physics, math

synthetic polymer characteristics

plastic - capable of being molded polymer - large, high molecular weight molecule formed by joining together a large number of molecules of low molecular weight first synthetic plastic - 1870 - answer to contest to make artificial billiard balls plastics - now they fit needs that NO other materials can fit from artificial skin to high strength composites

plastic properties

plastics have an enormous range of properties, from soft and opaque to very hard and transparent the features which account for these range of properties are: - length of chain - 3D arrangement of chains - branching of chain - composition of monomer units - bonding BETWEEN chains - orientation of monomer units WITHIN chain

blood clotting

platelets (thrombocytes) help blood clot by forming a platelet plug, blood clots, or other mechanisms

biopolymers

polymer - large, high molecular weight molecule formed by joining together a large number of molecules of low molecular weight proteins - formed from amino acids carbohydrates - polyhydroxy aldehydes and ketones nucleic acids - complex high molecular weight biopolymers

time of death - body temperature

postmortem body temperature drops ca. 1.5ºF per hour (normal conditions - slower in cold conditions) faster in water affected by wind and insulation initial temperature may be abnormal altering calculation (fever) may rise in hot environments

blood spatter analysis

the examination of the shapes, locations, and distribution patterns of bloodstains, in order to provide an interpretation of the physical events which gave rise to their origin

forensic anthropology provides critical answers by understanding...

the structure and function of the bones of the human body how to determine if an object is bone or not how to determine if a bone is human bone how to determine how old a bone is how to construct a biological profile from skeletal remains how to prepare a facial reconstruction from a skull how to gain insight into how someone died by examining their bones how to process a crime scene contain bones what is forensic taphonomy

katle-meyer test

uses phenolphthalein blood + phenolphthalein + H2O2 yields a deep pink color can give false positives

death investigator

usually non-MD but highly trained and experienced

undetermined

when a classification cannot be reasonably made therapeutic complications: death occurred due to known and often predictable side-effects from appropriate medical procedures; misapplication of standard medical practice are not part of this category well-intentioned mistakes, including incorrect diagnoses, lead to death: these are properly classified as arising from a natural manner of death

blood origin - human or other source - precipitin test

when animals are injected with human blood they form antibodies to the human blood can isolate human antiserum (antibodies to human blood). human antiserum will react only with human blood antiserum can (has) been made similarly for many other animals works on old (dried for many years) and small samples of blood.

blood clots

when blood vessels are cut or damaged, the loss of blood from the system must be stopped before shock and possible death occur accomplished by solidification of the blood - a process called coagulation or clotting a blood clot consists of a plug of platelets enmeshed in a network of insoluble fibrin molecules

when?

when were you hurt? aging injures: gross inspection, color, texture contusions (bruise - color change such as purple/blue to yellow/brown to yellow/green), microscopic, inflammation, repair when did you die? rigor mortis, lividity, temperature

where?

where were you hurt? where did you die? taphonomy investigation of the scene and circumstances forensic pathologists usually do not make house calls record reviews - paramedics and hospital inconsistencies between findings at the scene and otehr data - autopsy

the case of the wills west 1903

1892 - english scientist Sir Francis Galton published a book entitled Finger Prints in which was laid out a method of classification of fingerprints 1897 - Indian Police officer Sir Edward Henry proposed a modified classification system which was adopted by Scotland Yard in 1901 -still the basis of the systems used in most English speaking countries 1901 - First official use of fingerprints in the USA by the New York City Civil Service Commission 1930 National fingerprint file set up in America by the FBI

cobbler's basement

1942 - Cincinnati Cobbler accused of murder of young girl in basement basement excavated and 18 bones found and a bunch of ribs incriminated cobbler - several other murders in area unsolved bone from: cow, five sheep, a turkey or goose, a rat, a pigeon, and an owl - none were found to be human

forensic fiber analysis

1979 to 1981: more than 25 males strangled, bludgeoned or asphyxiated the only clue was several of the bodies of fiber threads and a few also had strands of dog hair fibers were two distinct types: a violet-colored acetate fiber and a coarse yellow-green nylon fiber associated with carpets stakeout of river dumping ground: stakeout patrol heard a loud splash and stopped a white Chevrolet station wagon driven by Wayne Williams police searched Wayne Williams' home and found floors of Williams' home were covered with yellow-green carpeting, and he also had a dog comparisons from the samples removed from the victims showed good consistency with Williams' carpet

types of prints

latent prints visible prints plastic prints

loops

1 or more ridges entering from the side of the print, recurving and exiting from the same side opens toward little finger its ulnar and toward thumb it's radial pattern area surrounding the loop is a type line delta surrounded by type lines all loops have at least 1 delta

blood loss

40% blood volume loss, internally and/or externally, is required to produce irreversible shock (death) blood loss of 1.5 liters, internally or externally, is required to cause incapacitation

blood volume

8% of body weight 5-6 liters for males 4-5 liters for females

blood type - 3 ways

ABO and Rh testing additional blood groupings enzyme presence

steps of autopsy

External Examination Y-Incision Internal Examination Removal of the Brain Weighting the Organs Examination of Stomach and GI Tract Sample Collection Return Organs to Body Sew Up Y-Incision

back spatter

blood directed back towards the source of energy or force that caused the spatter

stages of decomposition

Fresh Stage (Days 1-2): Commences at death, ends when bloating is first evident. Breakdown of protein and carbohydrates into simpler compounds Bloated Stage (Day 2-6): Putrefaction begins. Gasses produced by anaerobic bacteria inflate the abdomen. Decay Stage (Days 5-11): Abdominal wall breaks - gasses escape - carcass deflates. Post-decay Stage (Days 10-25): In dry habitats, remains are skin, cartilage, and bones. In wet habitats, wet, viscous material in the soil under the remains. Dry Stage (Days 25+): Mainly bones and hair remain. Odor is primarily that of normal soil and litter. Can last several months to years.

forensic anthropology includes...

General Description Sex of decedent Age of decedent Ancestry of decedent Stature of decedent Assessment of trauma (ante-, peri-, post mortem) Pathologies noted

luminol test

Rx of luminol with blood produces a complex which can be seen by luminescence very sensitive - up to a 3,000,000 dilution of blood can be seen detects unseen samples and patterns does not interfere with later DNA testing

how an autopsy is performed

Step 1 - Access and Control of the Remains: Step 2 - External Examination: Step 3 - Opening the Thoracoabdominal (thorax and abdomen) and Brain Cavities: Step 4 - Removing Organs: Step 5 - Evaluation and Analysis of Sample: Step 6 - Closure:

the start of synthetic polymers

Wallace Carothers invented nylon and neoprene in a single creative burst in the early 1930's the inventor led us into the synthetic age, bringing synthetic rubber and fiber to DuPont and the world but Carothers was a troubled man which led to his inevitable fate -- suicide at the age of 41 - by a powerful combination of depression and alcoholism a biography of Carothers (Enough for One Lifetime) tells his story against the backdrop of the Depression

blood types

a blood group or blood type is based on the presence or absence of 2 proteins on the surface of red blood cells

transfer bloodstains

a transfer bloodstain is created when a wet, bloody surface comes in contact with another surface occasionally, a recognizable image of the original surface may be observed in the pattern, such as a hand or shoe pattern subdivided into Contact bleeding, Swipe or Smear, Wipe, and Smudge

mechanism of death

altered physiology by which disease/injury produces death (arrhythmia, exsanguination)

proteins

amino acids are linked by amide groups called the peptide bond form shapes such as helicies and sheets--- hydrogen bonds are weak electrostatic bonds between H and O

when an autopsy is performed

any unattended or unexplained death when a physician is not available or willing to sign a death certificate; any unexpected death that takes place under unusual, unexplained, or suspicious circumstances suggesting foul play; any death resulting from homicide, suicide, or certain types of accidents; any death that could pose a risk to the public health; any death that takes place while the person is in legal custody; any employment or occupational-related death; any death of an institutionalized person for reasons other than illness; any death from a standard "lower-risk" medical procedure; any hospital death when the person is pronounced dead on arrival or occurring within the first 24 hours of being admitted unconscious; any death that appears to be the delayed result of a previous injury, especially when the injury resulted from criminal actions; any death where the body will be cremated

hair - class evidence

appendage of the skin that grows from a follicle resistant to chemical decomposition and long term structural stability can often determine body area where the hair originated and sex of owner can occasionally determine racial origin (anthropology terms) negroid: often kinky with dense uneven pigment flat to oval in shape caucasoid: often straight or wavy, fairly evenly distributed pigment, oval to round shape

medical examiner

appointed by government, licensed MD or DO

medicolegal investigations

assigns responsibility regarding the causation of an injury or ailment abuse and human rights Issues liability cases (e.g., drug interactions, malpractice medical "misadventure", etc.) patient rights protection, advance healthcare directives clinical pathology (e.g., non-accidental injury, abuse, assault, and rape), describe cause, severity, description, etc. mental competence death investigations: focus of this chapter.

the cuticle and medulla are...

best used tp distinguish if the sample is animal or human

natural polymers

biopolymers, proteins, polysaccharides, nucleic acids, and others such as spider's web, wool, asbestos, graphite, etc...

two types of blood evidence

blood biochemistry analysis and pattern analysis

type ab

both proteins are present

time of death

can estimate the time of death from: body temperature (algor mortis), estimate: 98.6 - rectal temp/1.5 rigor mortis (temperature dependent, muscle fibers become cross-linked and fused/ATP depletion, muscles stiffen/not contract, first noticed 2-4 hours postmortem, max 8-12 hours and remains 12-24 hours insect action - forensic entomology stomach content - stage of digestion last known activity - last sighting or the newspaper/mail normal postmortem changes

algor mortis

can estimate time of death from body temperature muscle fibers become cross-linked and fused ATP depletion muscles stiffen/not contract first noticed 2-4 hours postmortem max onset 8-12 hours remains 12-24 hours

determinations of manner of death

can it be changed? when and how? criminal injury related?

dusting

carbon metal magnetic powders

4 broad determinations to be made by a forensic pathologist

cause of death mechanism of death manner of death time of death

plasma characteristics

clear, yellowish fluid, sometimes appear milky after a very fatty meal or when people have a high level of lipids in their blood 90% water and the rest is protein blood that is allowed to clot and then filtered is blood serum--- contains none of the clotting factors

contusions

color changes a bruise goes through can give rough estimate of time of injury dark blue/purple (1-18 hours) blue/brown (~1 to 2days) green (~ 2 to 3 days) yellow (~3 to 7 days) assumes person is healthy

when comparing hair...

color, length, and diameter are important

ninhydrin method

colorless compound reacts with amino acids in sweat to form a colored compound

bullet wounds

contact wound: muzzle applied to skin at shooting. Impression of muzzle burned around entrance wound and absence of fouling and stippling contact wounds over skull have stellate appearance from expulsion of hot gases from barrel blowing back toward exterior rip apart skin around entrance wound close range (6-8 inches): entrance surrounded by fouling- soot traveling for short distance; stippling intermediate Range (1.5- 3.5 ft.): No fouling; hot fragments of burning gunpowder; "ball" and "fake"stippling at entrance wound distant (greater than 3.5 ft.): No soot or burning propellant; clean wound margins entrance wound: rim of abrasion dragging surrounding skin exit wound: projectile penetrates skin and pushes in outward

visualizing prints - superglue

cyanoacrylate ester when vapors come into contact with fingerprints the molecules of the cyanoacrylate attach to the print and polymerize the visible prints produced are white, but are often treated with a fluorescent dye to improve visibility

suicide

death brought about intentionally by the person who dies themselves in an effort to end their own lives

homicide

death caused by another individual, whether by intent, through negligent actions, or inadvertently differentiate between the level of intent used to bring about someone's death: on purpose - murder and homicide charges and without intent - leading to manslaughter charges

forensic anthropology

defined as "the field of study that deals with the analysis of human skeletal remains resulting from unexplained deaths." often done in a legal context an applied science five subdisciplines: 1. Biological, or physical anthropology 2. Archaeology 3. Cultural anthropology 4. Linguistics 5. Applied anthropology

medulla

either absent or ca. 1/3 the diameter of the shaft continuous, interrupted, segmented, or absent

coroner

elected official, may have no medical experience

hair is best identified by...

examining the medulla and cuticle

luminescence

excitation of a molecule can happen in several ways including absorption of light or as a result of a chemical reaction an excited molecule will lose energy with the electron falling back down the energy staircase to the ground state for some molecules the excess energy is lost in the form of light, it is this process that is known as luminescence a common application of luminescence is washing powder that contains optical brightener the optical brightener is a fluorescent dye that shows a blue luminescence when excited by the ultraviolet radiation present in sunlight luminescence is used forensically to detect fingerprints, it also found application in de-bunking the fake Hitler diaries some components of sweat are luminescent and fluoresce when illuminated with lasers and also, fluorescent dyes can be employed that do not require laser excitation.

MRI disadvantages

expensive

forensic mycology

explain cause of death from poisons and toxins help determine the location and time of death ties person or evidence to a particular place

fingerprints

form by contact of friction ridges on hands, feet, or lips with an object friction ridges assist in our ability to grasp and hold onto objects - approximately 2,700 ridge "units" per square inch of friction skin pore openings present on surface id the friction ridges fingerprints formed underneath the skin in the dermal papilae and as long as that layer is there, fingerprints will always come back

manner of death

homicide, suicide, accidental, natural, undetermined

types of genotypes

iAiA or iAi - Both genotypes produce the A protein (type A) iBiB or iBi - Both genotypes produce the B protein (type B) iAiB - This genotype produces the A and B protein (type AB) ii - This genotype produces no protein (type O)

biometrics

identification of humans by measurable physical traits

MRI advantages

images soft tissues (only those with hydrogen atoms (almost all "soft" tissues). images function through the use of contrast media

plastic prints

impressions of fingerprints in soft media

antibodies

in the blood type a - b antibody is present type b - a antibody is present type ab - neither a nor b antibodies present type o - both a and b are present

cause of death includes...

injuries always take precedence over disease for determining the cause of death includes things like blunt-force trauma, sharp force trauma, drowning (asphyxia), etc.

asphyxia and strangulation

insufficient amounts of oxygen reaching brain or essential organs of body natural diseases can shut down respiratory Emphysema, pneumonia, flu, asthma, larynx disorders asphyxiate causes of asphyxiation: drowning and smothering strangulation: homicidal, suicidal, accidental homicidal strangulation done manually- brute force choking around neck homicidal strangulation by ligature using rope, wire, or garrote hanging victim dies from pressure of body weight or neck breaks

latent prints

invisible to the naked eye and must be developed to see

visualizing prints - iodine

iodine sublimes at room temperature if an object is placed in a chamber with crystals of iodine placed in it, any fingerprints on the object will appear as brownish prints the iodine is believed to dissolve in the skin oils that make up the print (temporary and will fade)

wayne williams

key suspect in the Atlanta Child Murders in January 1982, he was found guilty of the murder of two adult men after his conviction, the Atlanta police declared an additional 22 of the 29 child murders solved hairs and fibers on one of the victims' bodies were found consistent with those from Williams' home, car, and dog

types of wounds - trauma

lacerations incised wound puncture abrasion contusion gunshot

cortex

main body of hair shaft, contains pigment granules, shape

is it bone? is it human bone?

microscopic macroscopic anatomy

visualizing fingerprints

most important method of detecting latent prints is to dust using a fine powder that adheres to the traces of oil and sweat aluminum dust, which is grey and highly visible on dark and mirrored surfaces carbon black for white surfaces luminescent powders which fluoresce under ultraviolet light magnetic powders other colors are available. dusting is suitable for hard and/or non-absorbent surfaces, for porous surfaces like paper or cloth another approach is needed

autopsy

not everybody needs autopsy not all are complete autopsies

a fingerprint is an individual characteristic

not the shape of the print that is individual, but rather the number, location and shape of specific ridge characteristics (also known as minutiae) courts often require 14-16 matched minutiae for a positive match will remain unchanged during an individual's lifetime fingerprints have general ridge patterns that permit them to be systematically classified

Karl Landtseiner 1900

noted that when blood from different people is mixed it sometimes forms precipitate--- deadly if mixed in body

type a

only the a protein is present

type b

only the b protein is present

synthetic polymers

organic polymers synthesized from organic monomers

blood stain evidence may reveal

origin(s) of bloodstain distance of bloodstain from target direction from which blood impacted speed with which blood left its source position of victim & assailant movement of victim & assailant number of blows/shots

blood in the veins

oxygen-poor it has unloaded its oxygen to the body's cells (exchanging O2 for CO2) and must now return to the lungs to replenish the supply of oxygen oxygenated: red deoxygenated: very dark red

white blood cells aka leukocytes

part of the immune system and fights infection circulate in blood to be transported to an infection site when WBCs increase, it is a sign of infection in the body

bloodstains

patterns created by same volume of blood, from same source to target distance

antemortem

prior to death

antibody

protein produced by the immune system of humans and higher animals in response to the presence of a specific antigen

blood's cellular components

red blood cells yellow platelets t-lymphocyte is light green

cellular portion of blood

red blood cells, white blood cells, and platelets

surface tension

resistance to penetration and separation surface acts to reduce surface area smallest surface area to volume ratio is offered by sphere

drowning

results from inhalation of water causing choking rapid formation of mucus in throat and windpipe "Foam cone" covers mouth and nostrils of drowned victims "Dry drowning" occurs from shock and enlargement of larynx. No fluids found in lungs or stomach Classic Drowning Stages: Surprise- person stunned and inhales water Holding breath- Person holds breath while struggling Pink foam- Inhales deeply and pink foam expelled Respiratory arrest- Thoracic movement and pupils dilate Final Struggle- 3-4 quick attempts to breathe and find air

Rh factor

rhesus monkey where it was first identified either present + or absent - o+, a+, ab-

normal postmortem changes

rigor mortis livor mortis desiccation putrefaction autolysis

burn and blunt force wounds

scorching or burning of skin leads to sepsis and is immediate cause of death wounds caused by heat, chemicals, or electricity fire victims found in "pugilistic" position: clenched fists, resembling pose of boxer heat causes protein in body to contract blood and lung samples taken blunt Force trauma results from clubbing, kicking, or hitting the victims the blow produces a crushing effect on the human body, resulting in contusions, abrasions, lacerations, fractures, or rupture of vital organs. red-blue contusions are always present, but this varies by the weight of the individual (obese people bruise easier than lean people)

fiber analysis non-hair

synthetic or natural (plant and mineral) polymeric characteristics: color, diameter, birefringence, shape, presence or absence of delustering particles rayon: classified as regenerated fiber (derived from natural material-cellulose), first man-made fiber 1911

angle of impact

the acute angle formed between the direction of a blood drop and the plane of the surface that it strikes

agglutination

the antibodies glue together the antigens from different red cells thereby sticking the red cells together forming "islands" blood mostly remains liquid with clotting, however, it does not remain a liquid

biometrics and key indicators

the application of statistical methods to biological data, is based upon finding some individualized trait that a person has that can distinguish them from all others universality uniqueness permanence measurability ease of use

trypanosoma brucei protozoa

the cause of african sleeping sickness

mycology

the study of fungi

palynology

the study of pollen, spores and similar materials along with the organic matter and traces of rocks and soils

soils and sediments

the study of the organic and inorganic matter found in soils and rocks

postmortem interval (pms)

the time between the actual death and finding the body

gunshot wounds

things for pathologist to learn: type of firearm distance of gun to victim entrance vs exit wounds track of projectile stippling - powder burns on the skin when the gun is inches to a few feet from the victim

blood type genetics

three forms of the gene (alleles) that control the ABO blood group, designated as iA, iB, and i two alleles (one from the mother and one from the father) form a persons genotype the inheritance of the alleles is co-dominant - if the allele is present, it gets expressed blood type does not necessarily tell you which alleles you have. It is possible for two parents with the same blood type (A or B) to have a child with type O blood both parents would have to have a mixed geno

type o-

universal donor has no protein to cause clumps or coagulation

type ab+

universal receiver the recipient has all of the proteins and will not forms clumps or coagulation

accidental

violent, unexpected death that was not caused by any intentional or criminal act by another person

HIV

virus that causes AIDS and infects white blood cells

who are you?

visual ID by friends or family ID cards and papers physical traits including scars and tattoos radiographic comparison fingerprint comparison dental comparison DNA testing

MRI - magnetic resonance scecptroscopy nmr

visualize soft tissue by measuring proton (nuclear) magnetic alignments relative to an external magnetic field

six critical questions of a body

who are you? when did you become ill? when were you hurt? when did you die? where did you get hurt? where did you die? did you die as a result of violence, natural causes, or a combination of both? if violence was completely or partially responsible for your death, was it suicide, accident, homicide, or undetermined? if someone killed you, who did it?

biomedical imaging

x-ray ultrasound CT MRI

forensic fingerprints

your fingerprint patterns are hereditary they are formed before a person is born they are unique and they never change gloves don't necessarily stop fingerprints prints can be left through surgical gloves gloves can also be turned inside out to yield fingerprints from the inside surfaces leather gloves leave prints that are unique to that glove and no other - leather comes from cow skin, sim. to human skin) even cloth gloves, such as mittens, can leave a distinctive print that can be traced back to the mitten that made it