Evidence Collection Flashcards

Which characteristic of a crush damage profile is MOST useful for determining the vehicle's closing speed in a frontal barrier equivalent (FBE) analysis?

Answer: The depth and distribution of crush across the vehicle's front

Crush depth and its distribution across the vehicle width are the primary inputs to stiffness-based (Campbell) energy methods used to calculate delta-V and closing speed.

A reconstructionist finds a gap in the skid mark evidence where tires momentarily stopped skidding before resuming. This gap most likely indicates:

Answer: ABS activation cycling during the braking event

ABS systems rapidly modulate brake pressure, causing the tire to alternately lock and release, producing characteristic gap patterns in the mark sequence.

When surveying a crash scene that spans multiple lanes of a highway, what is the preferred sequence of evidence documentation before any scene is cleared?

Answer: Overall scene photographs, then close-up photos, then measurements and sketches

Overall photographs establish scene context, close-ups capture specific evidence detail, and measurements/sketches follow to minimize scene disruption and preserve spatial relationships.

The Daubert standard, as it applies to crash reconstruction evidence, requires that the expert's methodology be:

Answer: Based on peer-reviewed, testable science with known error rates

Under Daubert, courts evaluate whether scientific testimony is based on sufficient facts, uses reliable methods that have been tested and peer-reviewed, and whether the method has been applied reliably to the case facts.

Which EDR data parameter is MOST directly useful for determining whether a vehicle's brakes were applied in the 5 seconds before a crash?

Answer: Brake switch status recorded in the pre-crash data frame

EDR pre-crash data records brake switch status on a time-stepped basis, directly indicating whether the driver actuated the brake pedal and when.

When reconstructing a crash involving a vehicle that caught fire, which evidence preservation priority should the reconstructionist emphasize?

Answer: Photographing and mapping all identifiable physical evidence before fire investigation removes debris

Fire scenes are volatile and rapidly altered by suppression efforts and investigation; prompt photography and spatial documentation of all physical evidence preserves the pre-disturbance state.

A reconstructionist notes that a vehicle has pre-impact tire marks from both front and rear axles that progressively widen apart laterally. This pattern is characteristic of:

Answer: A vehicle entering a yaw (rotating about its vertical axis) before impact

Progressively diverging tire marks from front and rear axles indicate the vehicle's rear was swinging outward relative to the front — the defining signature of a yaw maneuver.