ETC Laboratory Analysis & Forensic Science Flashcards
6 cards from real ETC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 ETC Laboratory Analysis & Forensic Science flashcards as text
What is locard's exchange principle and how does it apply to forensic analysis?
Answer: Every contact leaves a trace — evidence is transferred between persons and crime scenes during contact
Locard's Exchange Principle states that every contact between two objects results in material transfer, forming the basis for trace evidence analysis.
Which reagent is used as a presumptive test for blood that produces a luminescent reaction?
Answer: Luminol
Luminol reacts with the iron in hemoglobin to produce chemiluminescence, allowing detection of blood even when diluted or cleaned.
What is the role of a forensic laboratory's evidence custodian?
Answer: To maintain chain of custody records and control access to submitted evidence
The lab evidence custodian is responsible for receiving, logging, storing, and tracking all submitted evidence to maintain an unbroken chain of custody.
Why must forensic analysts wear PPE including gloves and masks when handling evidence?
Answer: To prevent cross-contamination of the evidence with analyst DNA or materials
PPE prevents the analyst's DNA, fingerprints, or other materials from contaminating evidence, which could invalidate results or compromise a prosecution.
Which type of evidence requires refrigeration at 2–8°C upon submission to the forensic laboratory?
Answer: Biological samples such as blood, saliva, and semen swabs
Biological samples degrade rapidly at room temperature; refrigeration at 2–8°C slows bacterial growth and enzymatic breakdown to preserve DNA integrity.
What does a 'confirmatory test' in forensic analysis provide that a presumptive test does not?
Answer: A definitive, scientifically validated identification of the substance
Confirmatory tests use validated instrumental methods (e.g., GC-MS) to provide a definitive identification that is admissible as conclusive evidence in court.