Evidence Collection & Preservation Flashcards

How long should fire scene evidence typically be retained after an investigation is closed, according to best practices?

Answer: Until the statute of limitations expires or all legal proceedings are concluded

Evidence should be retained until all potential legal proceedings are concluded and the statute of limitations has expired to avoid spoliation claims.

When multiple agencies respond to a major fire scene, who generally has primary responsibility for evidence collection and scene control?

Answer: The jurisdiction with legal authority over the scene, typically the local fire investigator or lead law enforcement agency

Jurisdictional authority governs scene control; while agencies cooperate, the legally authorized jurisdiction coordinates and leads evidence collection.

An investigator discovers a matchbook at the fire scene. Which of the following is the correct procedure?

Answer: Photograph it in place, note its exact location, then use gloves and forceps to package it in a paper or breathable container for fingerprint examination

Small items like matchbooks must be photographed in place, then collected with minimal contact to preserve potential fingerprint and DNA evidence, using breathable packaging to prevent mold.

What is the purpose of a scene examination log (or scene entry log) during a fire investigation?

Answer: To document every person who enters the scene, supporting chain of custody and scene integrity

A scene entry log records all persons who enter the evidence area, which is essential for maintaining chain of custody and defending evidence integrity in court.

When collecting biological evidence (blood, tissue) at a fire scene, what is the most critical storage consideration?

Answer: Biological evidence must be refrigerated or frozen and kept separate from chemical samples to prevent degradation

Biological evidence degrades rapidly at warm temperatures and must be refrigerated or frozen; it must also be kept separate from chemical samples to prevent cross-contamination.

In Oregon, which standard reference guide is most commonly cited by fire investigators when determining proper evidence collection and documentation procedures?

Answer: NFPA 921: Guide for Fire and Explosion Investigations

NFPA 921 is the nationally recognized scientific and technical reference for fire and explosion investigation methodology, including evidence collection procedures.

An investigator discovers a pour pattern on a hardwood floor with a sharp, irregular boundary. What does this pattern potentially indicate, and how should the boundary be documented?

Answer: A potential ignitable liquid pour; photograph and measure the entire boundary, noting its irregular edges and any surrounding low-burn indicators

Sharp, irregular boundaries on flooring are a potential indicator of poured ignitable liquids; the entire perimeter and surrounding burn depth must be documented and sampled.