Evidence Collection and Preservation Flashcards
6 cards from real ABMDI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Evidence Collection and Preservation flashcards as text
Why should biological evidence (blood, tissue) be collected into paper bags rather than plastic bags?
Answer: Plastic traps moisture, promoting bacterial growth that degrades DNA and may cause mold contamination
Moisture trapped in plastic promotes bacterial growth and can degrade biological evidence. Paper bags allow air circulation, preserving the integrity of biological samples.
What is the primary purpose of collecting a control sample at a death scene?
Answer: To identify background contamination at the scene that might confound laboratory analysis
Control samples (blank swabs or substrate controls) are collected to detect any pre-existing contamination at the scene that might affect the interpretation of evidence analysis.
When collecting bloodstain pattern evidence at a scene, the MDI should prioritize:
Answer: Thorough photography and documentation before any collection or disturbance
Documentation through photography must occur before any collection begins to preserve the spatial and contextual information of bloodstain patterns.
Vitreous humor is frequently collected for toxicological analysis during death investigations because:
Answer: It is relatively isolated and protected, making it less susceptible to redistribution and decomposition than blood
Vitreous humor is isolated in the eye and protected from postmortem redistribution of drugs, providing more reliable drug and alcohol concentrations than blood in advanced postmortem intervals.
What is the appropriate way to package and preserve a firearm collected at a death scene?
Answer: Document, render safe if loaded, photograph in place, then package in a paper bag with a label noting LOADED if applicable
Firearms must be documented in place, safely rendered unloaded by qualified personnel, photographed, and packaged in paper bags with appropriate labels including loaded status.
During scene investigation, the MDI identifies a substance suspected to be a controlled drug. What is the appropriate collection procedure?
Answer: Photograph the substance in place, collect using appropriate containers, seal and label with chain of custody, and submit to the laboratory
Suspected controlled substances must be photographed, properly collected with appropriate PPE, sealed in evidence containers, and submitted through formal chain-of-custody channels to the laboratory.