Traffic Crash Investigation Unit (TCIU) officers are specially trained investigators in traffic accident reconstruction and investigation. These officers have taken numerous accident investigation trainings conducted by the Institute of Police Technology Management (IPTM). TCIU Officers are called to the scene of all serious and fatal vehicle traffic accidents.

For traffic accident investigators, the moments immediately following the motor vehicle accident are crucial. Officers must work quickly and confidently to preserve significant physical evidence from the accident scene before it is altered or disappears. Officers must also anticipate what information will be needed for enforcing traffic laws, planning accident prevention and litigating accident cases. In addition, they must properly document the data for these various uses because once the scene is cleared, this data may never be recovered.

Officers reconstruct the scene of a traffic accident to determine how the accident occurred. Describing the events of the accident, in more or less detail, is the goal of the traffic investigation unit. Officers collect information about an accident and analyze the information that has already been collected. In order to be successful in traffic accident reconstruction, officers must be skilled to prepare after-accident situation maps, classify and interpret vehicle damage, properly interpret marks on the road, and be proficient in algebra.