2Y Forensics

When a crime has been committed.

When is a forensic scientist needed?

Scottish Policy Authority.

In Scotland, who is responsible for still carrying out the majority of Forensic Science?

Biology.

Documents.

Chemistry.

Toxicology.

What are the FOUR main areas of forensic science analysis?

Blood, semen, other bodily fluids.

Hairs and fibres.

Blood pattern analysis.

DNA profiling.

What are the FOUR areas of analysis in forensic biology?

Any item with writing.

What, in the forensic analysis of documents, can be analysed?

Footwear, tool mark, tyre analysis.

Paint and glass analysis.

Explosive analysis.

What are the THREE areas of analysis in forensic chemistry?

Drugs or alcohol in the blood and urine.

Drugs or alcohol in organs and tissues.

Identification of illegal drugs and their purity.

What are the THREE main areas of analysis in forensic toxicology?

Every contact leaves a trace.

What is Locard's Principle?

TWO.

How many basic principles are their in forensic science?

Locard's Principle.

Physical Fit.

What are the TWO basic principles of forensic science?

Physical fit can prove beyond reasonable doubt the connection between a crime scene and a suspect.

What is the Physical Fit principle?

A mark left by something.

What is a trace?

Very small amounts of material.

What is trace evidence?

Hairs.

Fibres.

Glass.

Paint.

Soil.

DNA.

What are the SIX types of trace evidence?

Given description of suspect and look for markers that can link the suspect to the crime scene.

What is REACTIVE trace evidence?

Do not know who suspect is but found white fibres at the scene of the crime on the victim, then look for evidence of someone who has white clothing.

What is INCEPTIVE trace evidence?

Taping.

Shaking.

Vacuuming.

Swabbing.

Extracting.

What are the FIVE methods used to recover trace evidence?

Colour.

Thickness.

Physical fit analysis.

Chemical analysis.

Impact sites.

What are the FIVE things you would look for when analysing glass?

Any long, thin, flexible, solid object with a high length to transverse cross-section ratio.

What is a fibre?

Determining its source (human or animal).

What would you look for when analysing HAIR?

Acid phosphatase - found in male sperm.

What would you look for to identify if the substance is male sperm?

DNA.

What is sperm a good source of?

In males.

Where is p30 exclusively found?

Salivary amylase.

What would you look for to identify if the substance is saliva?

Bacterial / cheek cells.

What might SALIVA contain?

DNA.

What do RBCs and platelets NOT have any of?

Kastle Meyer Test.

Leuchomalachite Green.

Name TWO preliminary tests that can be ran for blood...

Due to gravity: drops, drips, pools.

Give THREE examples of passive blood stains...

Contact.

Smear.

Wipe.

Smudge.

Give FOUR examples of transfer blood stains...

By fermentation from grapes/cereal grains.

How is alcohol produced?

It contains byproducts and additives.

How does alcohol get its colour AND flavour?

C2H5OH

What is the molecular formula for ethanol?

Mouth —> Oesophagus —> stomach and small intestine —> Circulatory system; Brain; Kidneys; Lungs; Liver.

Describe the absorption and distribution of alcohol within the human body...

Quantity.

Concentration.

Contact time in GIT.

Food.

List FOUR factors affecting rates of absorption...

90%

How much of the alcohol is approximately metabolised?

Alcohol Dehydrogenase.

Aldehyde Dehydrogenase.

What ate the names of the TWO key enzymes involved in alcohol metabolism?

Make it easier for alcohol to be eliminated from the body.

What is the MAIN role of Alcohol Dehydrogenase and Aldehyde Dehydrogenase?

Alcohol dehydrogenase metabolises ethanol into acetyl aldehyde.

What is the FIRST step in alcohol elimination?

Aldehyde Dehydrogenase breaks down aldehyde into acetyl.

What is the SECOND step in alcohol elimination?

Aldehyde (toxic)

What is produced as a result of the FIRST step in alcohol elimination?

Acetyl.

What is produced as a result of the SECOND step in alcohol elimination?

In the liver.

Where do the TWO stages of alcohol elimination occur?

Microsomal Enzyme Oxidising System (MEOS).

What is MEOS?

50mg / 100mL in blood.

22μg / 100mL in breath.

107mg / 100ml of urine.

What are the THREE legal limits of alcohol in Scotland?

Blood Alcohol (mg / 100mL) x 1.3

What is the conversion factor to figure out Urine Alcohol concentration?

Blood Alcohol (mg / 100mL) / 2300

What is the conversion factor to figure out Breath Alcohol concentration?

Cmax (maximum concentration) — (t x elimination rate).

What is the equation for calculating the alcohol elimination rate?

9 - 27 mg / 100mL / hour in blood.

What is the range for alcohol elimination rate?

All things are poison and nothing without poison.

Solely the dose determines that a thing is not poison.

What is Paracelsus's Third Defence?

Cannabis.

MDMA (Ecstasy).

Heroine.

Give THREE examples of controlled substances...

Any drug subject to the Misuse of Drugs Act 1971.

What defines a controlled drug?

Metabolites within the hair can be detected for up to a period of 90 days.

Why is hair-analysis a common form of drug testing?

The study of the ADME processes over a period of time.

What is pharmacokinetics?

The study of the dose versus pharmacological response.

What is pharmacodynamics?

The study of genetic influences/variances on the ADME processes.

What is pharmacogenetics?

Absorption, Distribution, Metabolism, Excretion.

What does ADME stand for?

Sensitisation.

Tolerance.

Accumulation.

Bioavailability.

What are the FOUR factors affecting toxicity?

Oral, snorting, injection.

List THREE common ways amphetamines are administered...

Increased dopamine.

What is the result of consuming amphetamines?

Slow down/ inhibit the re-uptake of dopamine.

How do amphetamines result in increased dopamine?