Case Description

In the early morning hours, a pair of police cruisers respond to a call. Due to the time, they elect not to use their sirens to avoid disturbing the public. Further down the road, several youths are walking home from a party. Seeing the police cruisers approach, two elected to wait at the crosswalk. The third individual attempted to cross the road, with disastrous consequences. The police cruiser eventually came to a rest in a parking lot.


Steps Taken:

    • ARCCA’s accident reconstruction experts reviewed all available data of the incident, including the points of rest of the pedestrian and police cruiser.
    • The experts were able to review security footage from a business near the intersection, which included the two vehicles but not the collision.
    • ARCCA’s experts visited the site of the accident to perform an inspection, collecting data such as 3d laser scans of the intersection.
    • During their visit, an ARCCA vehicle drove the stretch of road, with cruise control set to the road’s speed limit. Footage of ARCCA’s drive through was acquired from the business, taken from the same security camera.
    • Experts analyzed the footage to conduct a time/distance analysis, determining the speed of the cruiser seen in the original footage.
    • Additionally, the two sets of footage were compared, to examine the time taken to cross the known distance visible to the camera.

Final Findings:

The case rested on the speed of the approaching police cruiser. The department had regulations governing the speed officers were allowed to drive, with different levels allowed based on whether their lights, sirens, or both were engaged. The cruisers were using their lights, but not sirens. In such a scenario, the regulations stated that the posted speed limit should be followed.

The stretch of road where the incident took place had a speed limit of 45 miles per hour. Estimates, based on the stopping distance of the cruiser and the throw distance of the pedestrian, put the speed at impact at approximately 80 miles per hour – well over what was allowed by the department’s regulations.

ARCCA needed an effective visual to demonstrate the difference in speed. By syncing both videos at the first visible sign of the vehicles, a rough starting point was established. Playing the videos forward, the cruiser clearly crosses the distance in much less time than the ARCCA vehicle. This not only confirmed that the vehicle was moving well in excess of the speed limit, but provided an elegant way of demonstrating it that to the jury.

One of the visuals generated by the ARCCA team.

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