BSFS General 3 — Questions and Answers
Question 1: What distinguishes 'class characteristics' from 'individual characteristics' in physical evidence?
- Class characteristics identify a single source; individual characteristics identify a group
- Class characteristics narrow evidence to a group; individual characteristics identify a unique source (Correct answer)
- Class characteristics are biological; individual characteristics are chemical
- Class characteristics are visible; individual characteristics require microscopy
Correct answer: Class characteristics narrow evidence to a group; individual characteristics identify a unique source
Class characteristics link evidence to a group (e.g., shoe brand), while individual characteristics uniquely identify a single source (e.g., specific wear marks).
Question 2: In questioned document examination, what is 'indented writing'?
- Writing deliberately obscured with ink
- Impressions left on underlying pages when writing on a top sheet (Correct answer)
- Handwriting that slopes downward
- Text printed below the baseline
Correct answer: Impressions left on underlying pages when writing on a top sheet
Indented writing refers to impressions made on underlying sheets when pressure from writing on a top page transfers to the pages below.
Question 3: What is the primary purpose of forensic odontology?
- Analyzing bite marks and identifying individuals through dental records (Correct answer)
- Estimating age from facial bone structure
- Comparing DNA extracted from tooth enamel
- Performing autopsies on dental professionals
Correct answer: Analyzing bite marks and identifying individuals through dental records
Forensic odontology uses dental records, bite mark analysis, and dental comparisons to identify deceased individuals or link suspects to crimes.
Question 4: Which of the following best describes 'luminol' and its use in crime scene investigation?
- A chemical that reveals latent fingerprints under UV light
- A chemiluminescent reagent that reacts with iron in hemoglobin to detect trace blood (Correct answer)
- A dye used to stain hair samples for microscopy
- A solvent used to dissolve gunshot residue
Correct answer: A chemiluminescent reagent that reacts with iron in hemoglobin to detect trace blood
Luminol reacts with the iron in hemoglobin to produce a blue chemiluminescent glow, allowing investigators to detect blood even after cleaning attempts.
Question 5: What is the significance of 'rigor mortis' in determining time of death?
- It indicates the manner of death
- It provides a general time window by the progression and resolution of muscle stiffening (Correct answer)
- It reveals the victim's blood type
- It shows whether the body was moved after death
Correct answer: It provides a general time window by the progression and resolution of muscle stiffening
Rigor mortis begins a few hours after death, peaks around 12 hours, and resolves by 24–48 hours, helping estimate the postmortem interval.
Question 6: In forensic firearms examination, what is a 'striation'?
- The caliber marking stamped on a cartridge case
- A microscopic scratch or groove left on a bullet by the barrel's rifling (Correct answer)
- The pattern of gunshot residue around a wound
- A serial number etched into the firearm frame
Correct answer: A microscopic scratch or groove left on a bullet by the barrel's rifling
Striations are unique microscopic scratches left by a gun barrel's rifling on a bullet as it passes through, allowing examiners to match bullets to specific firearms.
Question 7: What is 'trace evidence' in forensic science?
- Digital records left by a suspect's online activity
- Small quantities of physical material transferred during criminal activity, such as fibers or glass fragments (Correct answer)
- Faint ink marks on documents
- Partial fingerprints recovered from surfaces
Correct answer: Small quantities of physical material transferred during criminal activity, such as fibers or glass fragments
Trace evidence consists of tiny physical materials—fibers, hair, paint chips, glass—transferred during contact between people or objects.
BSFS General 3
What distinguishes 'class characteristics' from 'individual characteristics' in physical evidence?