If you have been a victim of a criminal offense, you should contact the nearest local law enforcement agency to conduct the investigation and file the appropriate criminal charges through the District Attorney's Office.
If you are attacked, YES you can press charges even if coming out on top. It is probably advisable to press charges, particularly if the evidence is on your side, because your assailant may otherwise claim that you were the aggressor and sue you. Can you sue someone for assaulting you?