BCJ Forensic Science and Criminal Evidence 1 — Questions and Answers
Question 1: What is the 'chain of custody' in forensic evidence?
- The ranking of detectives on a case
- The documented sequence of possession and handling of evidence (Correct answer)
- The order in which witnesses testify
- The hierarchy of a crime organization
Correct answer: The documented sequence of possession and handling of evidence
Chain of custody is the chronological documentation showing the seizure, custody, transfer, and analysis of evidence to ensure its integrity.
Question 2: Which forensic technique uses unique patterns in a person's DNA to link suspects to crime scenes?
- Ballistic analysis
- DNA profiling (DNA fingerprinting) (Correct answer)
- Toxicology
- Latent fingerprint analysis
Correct answer: DNA profiling (DNA fingerprinting)
DNA profiling, developed by Sir Alec Jeffreys, analyzes unique DNA sequences to match biological material from a crime scene to a specific individual.
Question 3: What does Locard's Exchange Principle state?
- Every suspect has an alibi
- Every contact leaves a trace (Correct answer)
- Evidence must be photographed first
- DNA is infallible
Correct answer: Every contact leaves a trace
Locard's Exchange Principle states that whenever two objects come into contact, they exchange trace materials, forming the basis of forensic trace evidence analysis.
Question 4: What type of evidence is a witness's verbal account of what they observed?
- Physical evidence
- Testimonial evidence (Correct answer)
- Documentary evidence
- Digital evidence
Correct answer: Testimonial evidence
Testimonial evidence is evidence given by a witness under oath describing what they personally saw, heard, or experienced.
Question 5: Which fingerprint pattern is the most common among the general population?
- Arch
- Loop (Correct answer)
- Whorl
- Composite
Correct answer: Loop
Loops are the most common fingerprint pattern, accounting for approximately 60–65% of all fingerprints in the general population.
Question 6: What is the purpose of an autopsy in a homicide investigation?
- To identify the weapon used
- To determine the cause and manner of death (Correct answer)
- To collect DNA evidence only
- To establish the time of the arrest
Correct answer: To determine the cause and manner of death
An autopsy is a post-mortem examination performed by a forensic pathologist to determine the cause, manner, and circumstances of a person's death.
BCJ Forensic Science and Criminal Evidence 1
What is the 'chain of custody' in forensic evidence?