To determine which person was operating a particular vehicle, the investigating officer's best approach is to...
1) ask a witness to identify the vehicles operator
2) interview each person at the accident scene and ask about his or her involvement
3) place a hand on the vehicle and ask, "who was operating this car at the time of the crash?"
4) wait until all information is gathered to complete the report before making any decisions as to who was operating which vehicles(s)