You may need the investigative skill of an attorney to do this. If you are being accused of causing a car accident, and you believe you were not at fault, it is important to act quickly. An attorney will want to go to the scene of the accident as soon as possible to preserve any physical evidence suggesting that you were not responsible. Statements from witnesses can also go a long way. Finally, your attorney will likely seek out footage from any cameras that may have been in the area.