Forensics Flashcards
What is Forensic Science?
The science of the law, designed to give impartial evidence.
What are the main areas of Forensic Analysis?
Biology
Chemistry
Documents
Toxicology
What is Locard’s Principle?
Every contact leaves a trace
What is the chain of custody/evidence?
Preserve the scene
Search for material of evidential value
Package and label collected material
Storage and transmission to the lab
What is Trace Evidence?
Very small amounts of material that can provide a link between a suspect and a victim or a victim and a locus.
What are the types of Trace evidence?
Hair Fibres Glass Paint Fragments Soil Vegetation DNA
What is a Reactive Trace?
You already know something about the suspect (e.g. suspect wearing a red cardigan described by witness, look for that on victim).
What is an Inceptive Trace?
Don’t know anything about the suspect, find red fibres on victim, make connection.
What factors can affect the rate of absorption of alcohol?
Quantity Concentration Contact time in GIT Food Stomach Emptying
Where can we find traces of Alcohol?
Blood Breath Perspiration Urine Saliva
How do you calculate Urine Alcohol Concentration?
Blood Alcohol x 1.3
How do you calculate Breath Alcohol Concentration?
Blood Alcohol /2300
What is Paracelsus’s statement about dose?
“What is there that is not poison? All things are poison and nothing without poison. Solely the dose determines that a thing is not poison.
Give some examples of controlled substances.
Heroine, LSD, Solvents, Cannabis, Any drug subject to ‘Misuse of Drugs act 1971’.
What does ADME stand for?
Absorption, Distribution, Metabolism, Excretion
Why is Blood Grouping still used?
It is useful for large scale screening.
Name some good sources of DNA for DNA profiling.
White blood cells
Sperm cells
Hair with roots
Vaginal fluid
Name some bad sources of DNA for DNA profiling.
Skin cells
Urine
Hair shaft
Faeces
Is DNA profiling foolproof?
No, can be confused with identical twins.
What methods are used for DNA profiling?
RFLP - Restriction Fragment Length Polymorphism
PCR - Polymerase chain reaction
Name some applications of DNA profiling.
Familial searching Cold cases Linking/identifying families Wildlife crime Ethical issues
What is Entomology?
The study of insects
What is Algor Mortis?
Body cooling rate:
Hours since death = 37 (Fahrenheit) - internal body temperature / 1.5
What is Livor Mortis?
Skin discoloration caused by pooling of blood.
