The traffic crash reconstructionist job specialty is created to provide the traffic crash investigation expertise required to investigate and determine the cause of vehicular collisions on the basis of the crash dynamics and the physical evidence available for inspection at the crash site.  This expertise generally is beyond that which is normally possessed or needed by officers investigating minor or uncomplicated traffic crashes. The department's traffic crash reconstructionist generally is assigned to investigate crashes involving fatalities, serious personal injury crashes with injuries likely to result in death or permanent disability, crashes involving village vehicles with significant property damage or personal injury, crashes occurring as a result of a police action (i.e. chase), crashes involving extensive damage to village property, and any other crashes where circumstances warrant the involvement of the reconstructionist.