ETC Item Collection 2 — Questions and Answers
Question 1: When collecting trace evidence such as hair or fibers from a victim's clothing, which tool is most appropriate?
- Forceps or tweezers (Correct answer)
- Rubber gloves applied directly
- Adhesive tape lift
- Vacuum sweeper only
Correct answer: Forceps or tweezers
Forceps or tweezers allow precise collection of individual trace items without cross-contamination from adhesives.
Question 2: A wet bloodstain is found on a carpet at a crime scene. What is the proper initial collection method?
- Cut out the carpet section and seal in a plastic bag
- Absorb with a sterile swab and allow to air dry before packaging (Correct answer)
- Apply a chemical fixative immediately
- Photograph only and leave in place
Correct answer: Absorb with a sterile swab and allow to air dry before packaging
Wet biological stains should be collected with a sterile swab, air-dried to prevent mold growth, then packaged in breathable paper packaging.
Question 3: Which of the following best describes 'substrate control' in evidence collection?
- Collecting a sample of the surface material near but not on the stain (Correct answer)
- Using a control swab to test the collection tool
- Running a blank sample through the lab instrument
- Documenting the background radiation level at the scene
Correct answer: Collecting a sample of the surface material near but not on the stain
A substrate control is an unstained sample from the same surface material collected near the evidence to detect background contamination.
Question 4: When should an evidence technician collect reference standards from a victim?
- Only after the suspect is identified
- As early as possible during the investigation (Correct answer)
- Only when specifically ordered by a prosecutor
- After all other scene evidence is collected
Correct answer: As early as possible during the investigation
Reference standards from victims should be collected as early as possible to preserve sample integrity and enable comparison analysis.
Question 5: A firearm is found submerged in water. How should it be transported to the lab?
- Removed, dried immediately, then packaged in paper
- Submitted submerged in the water in which it was found (Correct answer)
- Drained and sealed in a plastic bag with desiccant
- Air-dried on scene and then placed in a cardboard box
Correct answer: Submitted submerged in the water in which it was found
Firearms recovered from water should be transported submerged to preserve potential DNA and fingerprints that would be destroyed by drying.
Question 6: What is the primary purpose of using a bindle when collecting dry trace evidence?
- To keep evidence sterile from biological contamination
- To prevent loss of small particles during transport (Correct answer)
- To satisfy legal chain of custody requirements
- To allow X-ray examination without opening the package
Correct answer: To prevent loss of small particles during transport
A bindle (folded paper packet) secures small trace particles and prevents them from being lost, scattered, or mixed with other evidence.
Question 7: When collecting soil samples as evidence, what is the recommended minimum number of samples to collect from a questioned area?
- One composite sample from the center
- At least three samples from different areas of the questioned zone (Correct answer)
- Ten samples at fixed grid intervals
- A single sample of 500 grams minimum weight
Correct answer: At least three samples from different areas of the questioned zone
Collecting at least three samples from different areas of the questioned zone captures variability and provides representative comparison material.
ETC Item Collection 2
When collecting trace evidence such as hair or fibers from a victim's clothing, which tool is most appropriate?