I'm a retired Oklahoma City police sergeant with 27 years law enforcement experience and several years private sector experience. My background includes thousands of accident investigations, hundreds of accident reconstructions, traffic law enforcement and police speed radar instruction. During the last 11 years on the OCPD, I was assigned to the Signal 30 Squad investigating traffic fatalities and other specialized crashes. I’ve handled both criminal and civil cases for plaintiff/prosecution and defense. My training includes courses with Northwestern University, IPTM, Texas A&M and others. Please note that I'm no longer active in this business, this site is for information only.
A piece of advice: Photos photos, photos!! If you are involved in a crash, and you're not disabled, take as many photographs as you can. Take photos of all sides of your vehicle, damaged or not, as well as of any other vehicles involved in the crash. Photos of all other involved parties can also be useful if you can get them without violating their privacy. Video may be of benefit too. With digital cameras and cell phones so readily available there is no excuse for not taking as many photos as you can. Take photos of the scene and any marks on the roadway, and traffic signs too. Do not interfere with the police or other first-responders and make sure you take the photos safely without endangering yourself or others. Even if it's dark and visibility is bad, shoot the photos anyway; underexposed photos can sometimes be enhanced later. The bottom line is to take as many photos as you can. It's better to take too many than too few.