According to the National Highway Traffic Safety Administration, almost 78 percent of all car accidents are caused by driver negligence. If you find yourself involved in a car accident, it is important to act quickly and do the right thing. Both the police and the medical reports are valuable evidence that can help your attorney prove that you suffered injuries from that particular accident. In addition, the police report may contain information about the witnesses, the movement of both vehicles prior to the accident, road conditions and how the accident came to be. On the other hand, a medical report will clearly show that you suffered injuries from that accident, making it easier to seek compensation for those particular injuries.