Crime Scene Reconstruction Flashcards

What is 'directionality' in bloodstain pattern analysis?

Answer: The determination of which direction a blood droplet was traveling when it struck a surface

Directionality refers to the direction a blood droplet was traveling, determined by the satellite stains and the elongation tail of the parent stain pointing away from the direction of travel.

A forensic reconstructionist is analyzing a fire scene. Which burn pattern indicates a fire's point of origin?

Answer: V-pattern or inverted cone shape on the wall

The V-pattern or inverted cone shape forms at the point of origin because fire burns upward and outward, creating a characteristic triangular burn pattern on adjacent walls.

In a staged crime scene, which finding would most strongly suggest staging rather than genuine burglary?

Answer: Drawers pulled out but valuables left behind while personal items are missing

Staged burglaries often show inconsistencies such as valuables being overlooked while specific items are taken, suggesting the perpetrator knew what to take rather than opportunistic theft.

What does 'muzzle-to-target distance' determination in gunshot wound analysis primarily rely on?

Answer: Gunshot residue stippling, soot deposition, and powder tattooing patterns around the wound

Muzzle-to-target distance is estimated by analyzing the distribution of gunshot residue, soot, and stippling (unburned powder) around the wound, which diminish with increasing distance.

Which principle guides the reconstruction of an event when physical evidence and witness accounts conflict?

Answer: Physical evidence takes precedence because it cannot lie, though witness perception errors are considered

In reconstruction, physical evidence is considered objective and takes precedence, while witness accounts may be affected by stress, perception limitations, or bias.

A cast-off bloodstain pattern found on a ceiling most likely indicates:

Answer: A bloody object such as a weapon was swung in an arc, releasing blood during backswing or forward swing

Cast-off patterns are created when a bloody object is swung and blood is flung off by centrifugal force, typically producing linear arcs on ceilings or walls.

In reconstruction of a vehicle collision, which evidence type best establishes the pre-impact speed of a vehicle?

Answer: Skid mark length combined with road surface drag coefficient calculations

Skid mark length analyzed using the drag factor of the road surface allows calculation of minimum pre-braking speed using standard kinetic energy formulas.