PCI Evidence Collection & Chain of Custody 2 — Questions and Answers
Question 1: When packaging biological evidence for laboratory analysis, investigators should:
- Use airtight plastic bags to preserve moisture
- Use paper bags or breathable containers to prevent mold growth (Correct answer)
- Seal evidence in vacuum-sealed pouches immediately
- Store wet biological evidence in sealed plastic to prevent contamination
Correct answer: Use paper bags or breathable containers to prevent mold growth
Biological evidence must be packaged in breathable containers like paper bags to prevent moisture buildup that leads to mold and degradation.
Question 2: A 'break in chain of custody' most seriously affects evidence by:
- Increasing the cost of the investigation
- Delaying the court proceedings
- Raising doubt about evidence integrity and admissibility (Correct answer)
- Requiring the investigator to recollect the evidence
Correct answer: Raising doubt about evidence integrity and admissibility
A break in chain of custody creates reasonable doubt about whether evidence was tampered with or altered, potentially making it inadmissible.
Question 3: In digital forensics, the concept of 'write blocking' refers to:
- Preventing unauthorized personnel from writing reports
- Using hardware or software to prevent modification of digital evidence during examination (Correct answer)
- Blocking write access to the case management system
- Encrypting digital evidence files during transfer
Correct answer: Using hardware or software to prevent modification of digital evidence during examination
Write blockers prevent any data from being written to digital storage media during forensic examination, preserving the original state of evidence.
Question 4: Which of the following best describes 'locard's exchange principle' as it applies to evidence collection?
- Evidence must be exchanged between jurisdictions before trial
- Every contact between two objects leaves a trace on both (Correct answer)
- Investigators must exchange evidence receipts with all parties
- Physical evidence always exchanges hands before court admission
Correct answer: Every contact between two objects leaves a trace on both
Locard's Exchange Principle states that when any two objects come into contact, material is transferred between them, forming the basis for trace evidence collection.
Question 5: When collecting latent fingerprints, the investigator should document them by:
- Photographing them before any processing or lifting (Correct answer)
- Lifting them immediately before they degrade
- Applying fingerprint powder before photography
- Comparing them to known prints before collection
Correct answer: Photographing them before any processing or lifting
Latent fingerprints must be photographed in place before any processing to document their original location and condition.
Question 6: A 'comparison sample' or 'known sample' in evidence collection is used to:
- Establish what was present before the incident occurred
- Provide a baseline for comparing against questioned evidence (Correct answer)
- Document the condition of evidence at the collection site
- Verify the integrity of the chain of custody documentation
Correct answer: Provide a baseline for comparing against questioned evidence
Known or comparison samples provide a reference standard from identified sources for laboratory comparison with questioned evidence samples.
Question 7: When an investigator receives physical evidence from another agency, the proper first action is to:
- Examine the evidence immediately to assess its condition
- Sign the chain of custody documentation acknowledging receipt (Correct answer)
- Repackage the evidence in new containers with new labels
- Contact the laboratory to prepare for incoming evidence
Correct answer: Sign the chain of custody documentation acknowledging receipt
Signing the chain of custody document upon receipt is the required step to maintain an unbroken and documented transfer of evidence.
PCI Evidence Collection & Chain of Custody 2
When packaging biological evidence for laboratory analysis, investigators should: