Sorry about the long absence of a reply... I looked more for any information about the mystery vehicle, and still have yet to find any specific information about it. As for the accident reconstruction, I can come up with a few theories: 1. The car went airborne it he course of the accident, and they were attempting to visualize how it then interacted. 2. They may have wanted to inspect under the car, and simply used a resource available to do it. One of the state troopers assigned to our coun is a reconstruction specialist, I haven't had a chance to talk with him about, but it's really amazing what all they can tell from a few sets of skid marks and the damage on a car. When it comes to requirements for staffing on assignments, there is really no definitive regulation. Local agencies are responsible for the development of their assignments and staffing requirements. There are minimum recommendations out there produced by the NFPA, NIOSH, etc. Most agencies follow these recommended practices, but they aren't necessarily required too. For cover assignments and manpower I've seen no explicit recommendations beyond the conventional idea that you need enough crew is truck to run it ,which usually amounts to a minimum of 3. Really what exactly responds, and where left to the discretion of the individual agencies because of how varied the needs are across the US.