Forensic Science Final exam

Forensic entomology

Study and practice of insects

List several types of documents that people have tried to produce counterfeit copies

Travelers checks, certain bonds, currency, coins, food stamps, postage stamps, and paper money

Controlled Substance

legal drugs whose sale, possession, and use are restricted because of the effect of the drugs.

Controlled Substance

A drug or other chemical compound who manufacture, distribution, possession, and use is regulated by the legal system

Synthetic fiber

A fiber made from a man-made substance such as plastic

Rifle

A firearm that has a long barrel; a long gun

Fully automatic

A firearm with a clipfed mechanism that fires repeatedly as long as the trigger is pressed

Textile

A flexible, flat material made by interlacing yarns

Pistol

A handheld firearm

Caliber

A measure of the inside diameter of a firearm barrel

Poison

A naturally occurring or manufactured substance that can cause severe harm or death if ingested, inhaled, or absorbed through the skin.

Semiautomatic

A pistol with a clipfed mechanism that fires one shot per pull of the trigger, the empty cartridge ejects and the next cartridge advances automatically

Revolver

A pistol with a revolving cylinder

Toxin

A poisonous substance naturally produced by certain plants, animals, and bacteria that is capable of causing disease or death in humans, a subgroup of poisons.

Monomer

A small molecule that may bond to other monomers to become a polymer

Polymer

A substance composed of long chains of repeating units

Explain why determining the time of death is important to forensics

A suspect may be proved innocent simply because he or she was not in the same same place at the time of death

Literary forgery

Refers to forgery of a piece of writing, such as a historic letter or manuscript

Crystalline

Regularly shaped; fibers composed of polymers packed side by side, which make it stiff and strong. Flax

Role of forensic toxicology

Examines the effects of poisons and drugs on the body

Explain when lividity first appears and how long after death it is fixed

2 hours after death, after 8 hours it's permanent

Drug

A chemical substance that affects the processes of the mind or body; a substance used in the diagnosis, treatment, or prevention of a disease; a substance used recreationally for its effects on the mind or body, such as a narcotic or hallucinogen

Mineral fiber

A collection of mineral crystals formed into a recognizable pattern

Describe different characteristics of fiber including: A. Type of fiber B. Natural of man-made C. Fiber color D. Number of fibers E. Weave pattern of fibers F. Relative thickness of the fiber

A. Type of fiber B. Natural of man-made C. Fiber color D. Number of fibers E. Weave pattern of fibers F. Relative thickness of the fiber

Explain the significance of why a forensics examiner would ask the following questions from the evidence collector when examining a fiber from a crime scene: A. Where was the fiber found? B. What was the source of textile that contained the fiber? C. What type of crime was committed? What was the time between crime and discovery of the fiber?

A. Where was the fiber found? Connection with victim and suspect B. What was the source of textile that contained the fiber? C. What type of crime was committed? Violent or non-violent What was the time between crime and discovery of the fiber? Carbon date, location, time, weather

Acute vs. chronic

Acute: caused by a high dose over a shot period of time (cyanide) Chronic: caused by lower doses over long periods of time.

Why does a crime scene investigator need to prove very specific information regarding temperature, amount of moisture present at the time when insects are found on decomposing body

Affect stages of decomposition which may effect the arrival of insects

4 factors that can affect the toxicity of a drug

Alcohol, time duration, and other drugs

Pesticide and characteristics of that drug overdose

Aldrin- anxiety, twitching, and heart rate

Explain what polyester, nylon, acrylic, and olefin all have in common

All man made synthetic fibers

Describe the effect if each of the variables on loss of body Temperature: Ambient temp Presence of absence of clothing Exercise prior to death Amount of air circulation

Ambient temp: affected by environment Presence or absence of clothing: will slow down heat loss Exercise prior to death : heat loss Amount of air circulation: depends on environment

Explain how the following factors may help solve a crime in which insect evidence was collected:

Amount of moisture Amount of light What part of the body the insect was found on the dead body Season of the year in which the insect was collected: can determine what stage the insect should be in Body locations: if body was moved Presence or absence of clothing on body: insects went on body

Narcotic

An addictive drug, such as opium, that relieves pain, alters mood and behavior, and causes sleep or feelings of mental numbness.

Distinguish between aerobics and anaerobic respiration

Anaerobic- absence of oxygen Aerobic- requires oxygen

Discuss which agent of bioterrorism could be easily transmitted in the form of white powder consisting of spores

Anthrax and bacillus anthracite

Three chemicals that are extremely toxic and used to kill people

Arsenic, cyanide, and strychnine

Examples of how the use of heavy metals being associated with acts of murder or homicide

Arsenic, lead, and Mercury

Describe the stages of decomposition of a corpse

As the body beings to decompose, blood seeps down through the tissue and settles into the lower parts of the body. Red cells. Begin to break down, spilling their contents. Hemoglobin, the substance in red blood cells turns purple when it spills out cells

Discuss the techniques used in gathering handwriting samples from a suspect

Ask suspect for their alibi

Explain why insects are attracted to a dead body

Attracted by smell of the first stage of decomposition

Explain why rayon is considered to be a regenerated fiber

Because ring ally it was natural but they changed it be synthetic

Explain why rigor mortis eventually fades

Because the muscles relax as the cells and muscle fibers begin to dissolve by Autolysis

Explain why blowflies are typically the first insects to lay eggs on a recently deceased person

Because they are attracted to the Samuel of first stage of decomposition

Describe what happens to muscles after someone dies

Begins to relax after Calle sand muscle fibers begin to dissolve by Autolysis

Technology has helped the forensic field by

Being able to be more accurate and do

Describe what happens to the body as liver mortis sets in

Blood turns purple, gravity, blood is drawn to floor or back of chair

Discuss the ecological succession of different insects as the body undergoes decomposition

Blowflies arrive first, attracted to first two stages of decomposition- putrescine and cadaverene. Then wasps come and lay eggs. Then cheese skippers which are attracted to the body fluids, lastly beetles and mites

Describe the type of research that is being conducted at the Body Farm in Tenn

Bodies are held in different environments and researched. Research of chemical charges after decomposition. Used to help find information on bodies

Describe the effect of each of the following variables to the onset of rigor mortis: Body temperature, ambient temperature,amount of body fat on the victim, amount of clothing on the victim, illness, amount of exercise prior to death, sun exposure

Body Temperature: cooler the body, slower the rigor Ambient temp: warmer the body, the faster rigor comes on Amount of body fat: body fat stores extra oxygen and will slow rigor mortis down Amount of clothing- the presence of clothing accelerates rigor mortis Illness- if fever, body temp higher- rigor mortis faster Amount of exercise- exercising before- rigor faster Sun exposure-a body with direct sun- warmer- rigor faster

Explain how body temperature is taken from a corpse

Body temp is taken through liver with thermometer

Matthieu Orfila and Robert Christison

Both made it possible to identify arsenic and other toxins in human tissue

List several examples of animal hair used in textile production

Bunny, sheep, alpaca

Describe some methods of examining fibers that result in destroying the fibers

Burn test- how does it react

Explain how to estimate the time of death of a person using insect evidence

By determine different stages of insects

Explain the importance of a medical examine collecting insect evidence as well as body, soil and air temperatures when trying to approximate the time of death

Can determine what should be happening to body

List examples of gases used as lethal agents

Carbon monoxide, potassium chloride, and hydrogen cyanide

Cause, symptoms, and treatment of tetanus

Cause- a poison that blocks nerve signals from the spinal cord to the muscles. Symptoms- lock jaw, muscle tension, broken bones

Distinguish among cause, manner, and mechanisms of death

Cause- reason for death Manner- natural, accidental, suicidal, and homicidal Mechanism- specific change in the body that brought about cessation of life

Discuss various types of organisms or chemicals that are considered potential bio terrorist agents

Cells and spores

Distinguish between cellular death and death of the organism

Cellular- when cells die due to lack of oxygen Organism death- whole organism shuts down

Definitions of death

Cessation or end of life. Irreversible cessation of circulation of blood. The heart stops beating and cannot be restarted. Cessation of all brain activity.

Describe different types of documents that people commonly forge

Checks, employment records, legal agreement, licenses, and wills

Describe how a counterfeit pen is used to detect counterfeit money. What chemical reaction occurs? Explain why authentic paper currency will not react with a counterfeit pen?

Chemical reaction: Iodine on starch- turns black. Real currency doesn't have starch which is why it doesn't react to the pen. Real money will have yellow stripe from pen

How can a substance such as wood alcohol can be indirectly toxic

Chemically converted to metabolites, in the human liver

Describe methods used by banks and businesses to try to prevent check forgery

Chemically sensitive paper Large font sauce- requires more ink and make alterations hard High resolution borders that are difficult to copy Mulitple color patterns Embed fibers that glow under different light Che,iCal wash detection systems that change color when a check is altered

Discuss methods used to altar paper or ink to make it appear like a much older document

Chemicals can be added to paper and ink to add age, watermarks impressed

Describe changes in the eyes following death. Cloudiness of cornea

Cloudiness of cornea- eye dries out, thin film observed, 2-3 hours if open at death, 24 hours if eyes closed at death Decomposition progresses at a predictable rate, build up of potassium

Compare and contrast the shape and length of muscles when they are contracted versus when they are relaxed

Contracted- presence of extra calcium Relaxed- cells and muscle fibers begin to dissolve

Describe the chemical composition of asbestos

Crystalline structure

Define algor mortis

Death heat and describes temperature loss in a corpse

Discuss why it's impossible to determine the precise moment of death

Death is a process rather than an instant event. The moment of death is usually considered the point of no return. When the heart stops beating, the cells of the body begin to die because they are no longer receiving a fresh supply of oxygen.

Define rigor mortis

Death stiffness

Describe chemical testing used to identify a fiber

Does it burn or. Curl? Does it Melt quickly or slowly

Explain the tole of a handwriting expert called to testify at a jury hearing. Describe how a handwriting expert attempts to convince a jury that a particular handwriting sample does or does not belong to a particular individual

Demonstrates how document comparison were made and how they were used to the suspects guilt or innocence

Describe some of the criteria for detecting counterfeit money in the US paper currency

Different symbols of hints on money itself

Distinguish between direct and secondary transfer of evidence

Direct: victim to suspect Secondary: source to victim to suspect

Illegal drugs

Drugs that are not currently accepted for medical use in the U.S. Example: heroin

Identify the different stages of blowfly development

Egg, larva, larva 2, larva 3, pre-pupa, early and late pupa, adult

Explain using specific examples, how different insects can fill different niches in relationship to a decomposing body

Eggs hatch and feed on nutritious decomposing tissues

Forensic entomology

The study of insects as they pertain to legal issues

Counterfeiting

False documents or other items are copied for the purpose of deceptions

Example if fiber evidence is considered to be class or individual evidence

Fiber evidence is class evidence

Explain how fibers are formed into yarns or rope

Fibers that are twisted together

Yarn

Fibers that have been spun together.

Explain the importance of forensics in determining the manner of someone's death

Forensic scientists are able to figure out manner of death, coroner may not be able to

Ballistics

The study of projectiles

Describe how handwriting analysis is being used in Forensics: Government institutions: Financial institutions:

Forensics: comparing suicide notes or ransom notes to other handwriting Government institutions: makes comparisons in court room, validates comparisons by showing similarities Financial institutions: Make sure documents are real. Make sure money is real

Distinguish between the terms forgery and fraudulence

Forgery- the making, adapting, or falsifying of documents or other objects with the intention of deceiving someone Fraudulence- when a financial gain accompanied a forgery

Identify the cause of the several accidental deaths from drugs among famous musicians, comedians,and actors

Georgi Markov- poisoned with Ricin by using tip of umbrella Vladimir Kostov- well clothed, Sam assassination attempt, but clothing prevented injection

Five types of controlled substances

Hallucinogens, narcotics, stimulants, anabolic steroids, and Depressants

Symptoms and signs of drug drug overdose

Hallucinogens: affects perception, thinking Narcotics: suppressing central nervous system Stimulants: feelings of energy and alertness Anabolic Steroids: promote cell and tissue growth Depressants: Relieve anxiety

Sources, effects on the body, and examples of hallucinogens, narcotics, stimulants, anabolic steroids, and depressants

Hallucinogens: source- plants, effects perception and thinking, Example- ecstasy Narcotics- Manmade pain killers, suppress central nervous system, heroin and morphin Stimulants- Increase feeling of energy amphetamines Anabolic steroids-similar structure to testosterone.Promote cell and tissue growth Depressants-relieve anxiety and produce sleep. Benzodiazepines

Overdose of alcohol

Headache, nausea, and weakness

Describe a famous case where someone has attempted literary forgery

Hitler diaries- tried to forge Hitlers diaries. A paper whitener was found on many of the pages and that had been invented until after Hitler committed suicide

Explain how it is possible to determine someone's body position when they died if a body was moved after death by examining the body for evidence of lividity

If they were sitting- lividity would be on body parts directly touching the chair

Larva

Immature form of an animal that undergoes metamorphosis (for example, a maggot)

2 ways heavy metals are ingested in the body

Ingestion and inhalation

Describe the different symptoms of Anthrax if absorbed through Inhalation- Ingestion- Skin absorption-

Inhalation- sore throat, cough, and fever Ingestion-Nausea, fever, and abdominal pain Skin absorption- itchy bumps

List 4 ways that people can be exposed to drugs

Inhaling, injecting, ingesting, and absorbing

Describe the toxic effect of lethal gases on the body

Inhibiting enzyme activity, interfering with production of ATP

Describe some of the technology used in handwriting analysis

Initial: naked eye, handheld lens, or a microscope More detailed: infrared spectroscope, biometric signature pads

Describe how ADH accumulated degree hours are used to calculate the time required for an insect to reach maturity

Insects raised under certain environmental conditions as crime scene, develop research

Three ways people can be exposed to toxic substances

Intentionally, deliberately, and accidentally

Describe three other substances other than drugs that are used to kill people

Lead, mercury, pesticides

Effects of toxins including Lead, mercury, arsenic, cyanide, and strychnine

Lead- Nausea, abdominal pain, insomnia, headache Mercury- Personality changes, headache, memory and balance issues Arsenic- Dryness of throat, muscle cramps, and difficulty speaking Cyanide- Weakness, confusion, and pink sink Strychnine- Body spasms and temperature rises

Describe the role of various types of toxins in causing death

Lethal drug combinations

Why is it necessary to collect weather information for the area around the body

Life cycles are affected by fluctuation in the Dailey environmental conditions

Describe 12 types of handwringing characteristics that can be analyzed in a document

Line quality, spacing, size consistency, continuous, connecting letters, letters complete, cursive or printed, pen pressure, slant, line habits, fancy curls or loops, and placement of crosses on t's and dots on i's.

Describe at least 4 ways to estimate the time of someone's death

Livor mortis Rigor mortis Algor mortis decomposition

Relate Locard's principle of Exchange to trace fiber evidence

Locard's principle-whenever 2 people come in contact, physical transfer occurs- any contact with another person, place, or thing results in exchange of physical materials

Describe why scanning of paper money does not produce authentic looking paper currency

Money has added features to the paper that when scanned, prevent the currency from being copied. It has microscopic detail and special paper

Distinguish between four manners of death: natural, accidental, suicidal, and homicidal

Natural- caused by interruption and failure of body functions, resulting from age or disease Accidental- Caused by unplanned events, such as a car accident or falling from a ladder Suicidal- someone purposefully kills oneself Homicidal- death of one person caused by another person

Distinguish between the two types of fibers Natural Man made

Natural: Fiber produced naturally and harvested from animal, plants, or mineral sources Man made: Fiber made from a man-made substance such as plastic

Discuss the reliability of measuring potassium levels in the eye for estimating someone's time of death

Not accurate

List examples of man-made (synthetic) fibers

Nylon, polyester, Rayon, Olefin

Discuss history of using insects to determine the time of death

Observes and collects data about environmental conditions including temp, moisture, and wind

Discuss why handprint samples from the same individual can differ with time

Once a person starts writing subconsciously and characters are habit, unique handwriting is formed

Manner of death

One of four means by which someone dies (Natural, accidental, suicidal, or homicidal)

Instar

One of the three larval stages of insect development

Describe ways people have tried to altar checks

Ordering another's checks from a deposit clip Altering check Intercepting authors checks, altering, and chasing it Creating a check from scratch

Why is ethyl alcohol considered to be organic

Organic because it is produced by the fermentation of sugar in fruits, grains, and vegetables

Explain the rod of each of the rolling in regards to rigor mortis Oxygen: Circulation: Aerobic respiration: Anaerobic respiration: Lactic acid: noticeable ATP:

Oxygen: lost causing cells to not to be able to get energy Circulation: none oxygen flow to the cell ceases Aerobic respiration: accelerates rigor Anaerobic respiration: slows down rigor Lactic acid: noticeable after someone has just worked out, rigor faster ATP: not able to be produced due to lack of oxygen

Different types of weave patterns

Plain Basket Satin Twill Leno

Contrast the chemical composition of animal fibers to plant fibers

Plant- cellulose and protein Animal- no cellulose, more protein

Describe sources of natural fibers, including animal hair, plant fibers, and silk

Plant- cotton, flax Animal- wool Silk- worm

Organic toxin

Poisonous substances produced by living organisms. Proteins that can be absorbed by another living creature, interferes with metabolism

Describe the cause, symptoms, and treatment of botulism

Produced by the bacterium Clostridium botulism. Cause- canned vegetables, curved pork, and ham. Symptoms0 muscle spasms, eye conditions, excessive sweating, and headaches. Treatment: cosmetic treatment

Recognize the stage of decomposition based upon: Odor Amount of decay Color of the flesh Amount of moisture in the flesh Build up of gases

Purple color, 6-10 days fluid leak, abdomen swells with carbon dioxide

Shell casing

The metal housing for the gunpowder of a firearm

Provide example of materials produced from the different parts of plants listed below: Seed fibers: Fruit fibers: Stem fiber: Leaf fibers:

Seed fibers: coconut, cotton Fruit fibers: coconut Stem fiber: hemp+flax Leaf fibers: Manilla

Describe the source of different textiles made from plants

Seed, fruit, stem, and leaf

Describe microscopic testing used to identify a fiber

Single or multicolored? Color, # of fibers, thickness, and shape

Provide an explanation why insects collected at a crime scene need to be immediately preserved

So they are able to detect time of death by stages of insect

Describe the variation in thickness, stiffness of different types of plant fibers

Soft, elastic, and absorbent

Discuss role of ricin as a bioterrorism agent

Source- castor oil Toxic- Lethal Absorption- inhalation, ingestion, skin, and eye Symptoms-fever, cough, dehydration, and low blood pressure

Explain the progression of rigor mortis from when it first sets in to. When it fades

Starts within two hours of death, starts in head moves down to legs. After 12 hours, body is in most rigid state. Stiffness disappears after 36 hours

Discuss the proper collection of insects at a crime scene Areas that need to be searched for insects How many insects should be collected Why are some insects immediately preserved and some are kept alive What type of information must be collected along with the insects Where are the insects send to be further examined

Temperature, moisture, wind, time of day, season, exposures. Preserved in same environmental conditions as crime scene, which leads to a more exact time of death

List at least 5 methods used to determine if a person has been exposed to drugs or other toxins

Tests done to check stomach contents, skin, hair, internal organs, and eyes

Explain how insect presence may be detected without actually finding the live insect

The body is torn apart and different parts of the body are eaten

Example of secondary transfer of evidence

The carpet from the suspects house, to the suspect, to the victim.

Death

The cessation, or end, of life

Algor mortis

The cooling of the body after death

Toxicity

The degree to which a substance is poisonous or can cause injury

Breech

The end of the barrel attached to the firing mechanism of a firearm where the art ridge is loaded and unloaded

Muzzle

The end of the barrel from which the projectile exits a firearm

Cause of death

The immediate reason for a person's death (such as heart attack, kidney failure)

Barrel

The long, metal tube that guides a projectile out of a firearm

Direct transfer

The passing of evidence, such as fiber, from victim to suspect or vice versa

Trajectory

The path of flight of projectile

Livor mortis

The pooling of the blood in tissues after death resulting in a reddish color of the skin

Decomposition

The process of rotting and breaking down

Bullet

The projectile that is released when a firearm is discharged

Lands and grooves

The ridges (lands) and depressions (grooved) found on the inside of a firearm's barrel that are created when the firearm is manufactured

Fiber

The smallest indivisible unit of a textile, it must be at least 100 times longer than wide

Mechanism of death

The specific body failure that leads to death

Rifling

The spiral pattern of lands and grooves in the barrel of a firearm

Autolysis

The spontaneous breakdown of cells as they self-digest

Pupa

The stage in an insects life cycle when the larva forms a capsule around itself and changes into its adult form

Rigor mortis

The stiffening of the skeletal muscles after death

Gunshot residue

The tiny particles expelled from a firearm when it is fired

Secondary Transfer

The transfer of evidence such as a fiber from a source, a carpet, to a person (suspect) and then to another person, victim

Discuss how time of death is an estimate that should be based on multiple factors not just one types of evidence

There are many factors that can effect rigor mortis, algor mortis, decomposition, and presence of insects and all of these aspects are researched in order to find out time of death

Brief description of how toxins have been used since Socrates

They have been used in human tissue

Distinguish between the terms: thread, yarn, and textile

Thread- flexible, flat material made by interlacing yarns Yarn- made up of textiles Textile- made together to create yarn

Discuss the role of fibers as a source of evidence in forensic investigations

To create a link between crime and suspect

Identify the major goal of a forensic handwriting analysis

To determine authenticity of the handwriting

Discuss why someone's stomach contents is emptied and examined during autopsy

To determine time of death by examining what food is present in the stomach

Drugs analyzed in forensic laboratory

Urine testing, blood testing, and hair testing

Describe several different methods used to locate and collect fiber evidence from a scribe scene

Vacuums, sticky tape, forceps,

Firearm

Weapon capable of firing a projectile using a confined explosive as a propellant

Describe physical characteristics used to identify a fiber

Weave pattern, stretch ability, appearance, and texture

Discuss counterfeiting of money: What type of crime is this considered- What government agency is responsible for handling counterfeit

What type of crime is this considered: federal felony, punishable up to 15 years in prison What government agency is responsible for handling counterfeit: U.S. Secret Service

Process of cellular Autolysis

When the cell membrane dissolves, enzymes and other cell contents spill out and digest surrounding tissues

Amorphous

Without a defined shape; fibers composed of a loose arrangment of polymers that are soft, elastic, and absorbing

Explain why knowing the degree of digestion of a deceased person could be useful in estimating time of death

Would determine the last time they ate, which could help lead to the time of death

Cartridge

a case that holds a bullet, primer powder, and gunpowder

Natural fiber

a fiber produced naturally and harvested from animal, plant, or mineral sources

Discuss how the use of technology has improved fiber examination using the following two methods A. Polarizing light microscopy B. Infrared microscopy

polarizing light microscopy- shows dyes and pigments Infrared microscopy- shows the smallest particles