Forensic Engineering Evaluation of Physical Evidence in Accident Reconstruction

Physical evidence deposited by vehicles as a result of an accident may not always be fully documented by the investigating law enforcement officers by means of measurements.

Many times, the investigating officers are able to document the location of the vehicles at rest, but can only measure and locate some of the related tire marks and/or gouges that may be present on the roadway as a result of the collision. The officers may further supplement their investigation by photographing the scene of the accident.

The photographs often depict the position and geometry of other physical evidence related to the roadway or other geographic features. However, the forensic engineer may require more detailed information regarding the physical evidence than is shown in the photographs or measured by the officers, and must therefore take further steps to extract it.

Depending on the evaluation required in the case, the forensic engineer would need to further analyze the accident by an inspection of the accident site and/or vehicles. After collecting the available information from the measurements made by the officers, the photographs taken at the scene, and the inspections by the forensic engineer, the data must then be compiled in a comprehensive form to further evaluate they dynamics of the accident.

This paper discusses three methods (Camera Matching, Photogrammetry, and Rectification) of collecting the physical evidence from several sources and the procedure of producing a comprehensive forensic map of the evidence relative to the roadway and the dynamic motion of the vehicle.