Impression and Pattern Evidence Flashcards
7 cards from real CSI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Impression and Pattern Evidence flashcards as text
What is a 'cast-off' bloodstain pattern?
Answer: Blood flung from a bloody object in motion, such as a swung weapon
Cast-off patterns are created when blood is released from a moving, blood-soaked object (e.g., a bat or knife) during the back-swing or follow-through.
When analyzing tire tracks, 'pitch sequence' refers to what?
Answer: The repeating pattern of different-sized tread blocks arranged around the tire circumference
The pitch sequence is the specific arrangement of differently sized tread elements around the tire, which is proprietary to each tire design and aids in brand identification.
Which of the following best describes a 'transfer' bloodstain pattern?
Answer: A stain created when a bloody surface contacts another surface, depositing blood
A transfer pattern results from direct contact between a bloody surface (such as a hand or shoe) and another surface, producing a mirror image or partial impression.
In footwear impression evidence, what does EEA stand for in the context of examination standards?
Answer: Exclusion, Elimination, Association — the three possible conclusions in footwear comparison
Forensic footwear examiners typically issue one of three findings: exclusion (shoe did not make the print), elimination (insufficient data), or association (consistent with having made the print).
What is the recommended first step before pouring a dental stone cast into a soil shoe impression?
Answer: Photograph the impression with and without a scale in oblique light
Photography with a scale under oblique lighting must be completed before any physical evidence is disturbed by the casting process.
A CSI observes a shoe print in blood that shows the heel but not the toe. What does this partial pattern most likely indicate?
Answer: Only the heel contacted the bloody surface, or the toe print was deposited elsewhere
A partial print with only the heel present suggests either the heel was the only part that contacted the blood pool, or the person stepped partially into the source area.
In tool mark examination, a 'compression mark' (also called an impressed mark) is produced how?
Answer: By a tool being forced perpendicularly into a surface under pressure
Compression marks are created when a tool is pressed directly into a softer surface, leaving a negative impression of the tool's face or edge.