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
