CFL Forensic Analysis & Evidence Handling 2 — Questions and Answers
Question 1: When photographing a lock cylinder for forensic documentation, which sequence is considered best practice?
- Close-up first, then mid-range, then overview
- Overview first, then mid-range, then close-up (Correct answer)
- Mid-range only is sufficient for forensic purposes
- Photographs are unnecessary if written notes are detailed
Correct answer: Overview first, then mid-range, then close-up
Forensic photography follows the overview-to-close-up sequence to establish context before capturing detail.
Question 2: A forensic locksmith finds bright, parallel scratch marks inside a keyway. These marks are MOST consistent with:
- Normal key insertion wear
- Pick manipulation attempts
- Impressioning tool activity (Correct answer)
- Bumping attack with a bump key
Correct answer: Impressioning tool activity
Impressioning leaves characteristic parallel scratch marks inside the keyway from the blank being worked against the pins.
Question 3: Which type of evidence packaging is MOST appropriate for a lock cylinder containing biological material (blood)?
- Airtight plastic bag to prevent contamination
- Paper bag or envelope to allow moisture to escape (Correct answer)
- Aluminum foil wrapped tightly
- Submerge in distilled water to preserve DNA
Correct answer: Paper bag or envelope to allow moisture to escape
Biological evidence must be packaged in breathable paper containers to prevent mold growth that degrades DNA.
Question 4: In forensic lock examination, 'toolmark striation analysis' compares marks using:
- A standard ruler and protractor
- Comparison microscopy between questioned and known tool marks (Correct answer)
- UV light illumination only
- Digital caliper measurements of mark depth
Correct answer: Comparison microscopy between questioned and known tool marks
Comparison microscopy allows direct side-by-side visual comparison of striation patterns from questioned and known tools.
Question 5: A deadbolt shows no external damage but the door frame is cracked. The forensic locksmith's report should note:
- Lock bypass, because the lock was not defeated directly
- Forced entry via structural compromise of the door frame (Correct answer)
- No forced entry because the lock is undamaged
- Picking, because no external damage is present
Correct answer: Forced entry via structural compromise of the door frame
When the lock is intact but the surrounding structure is damaged, the entry method is classified as forced entry through structural failure.
Question 6: The chain of custody for a lock submitted as evidence MUST include:
- Only the final examining lab technician's signature
- Every person who handled the item and the date/time of each transfer (Correct answer)
- The manufacturer's serial number as the sole identifier
- The property owner's written consent form
Correct answer: Every person who handled the item and the date/time of each transfer
A complete chain of custody documents every handler, date, and time to ensure evidentiary integrity from collection to court.
Question 7: Which microscopy technique is BEST suited for revealing fine surface toolmarks on a brass lock plug?
- Transmission electron microscopy (TEM)
- Stereo (comparison) microscopy (Correct answer)
- Fluorescence microscopy
- Atomic force microscopy (AFM)
Correct answer: Stereo (comparison) microscopy
Stereo microscopy provides the three-dimensional, low-magnification view needed to examine surface toolmarks on lock components.
CFL Forensic Analysis & Evidence Handling 2
When photographing a lock cylinder for forensic documentation, which sequence is considered best practice?