Going there yourself and trying to take a bike that you suspected but had not verified was your son’s bike and from someone whom you did not know was thief (assuming it was your son’s bike) was a very bad choice. Chasing the kid and grabbing the bike was even worse. And getting into a physical confrontation (if that is what occurred) with the mother over it and threatening (by implication) to shoot the kid if he drew the knife was way beyond what should have happened over a suspected stolen bike. If you know all the cops in that town, why didn’t you simply ask them to check out the bike? Surely they would have gone and looked for you, right? That is what you should have done. No bike is worth what happened here. You now face battery charges and unless you can convince the prosecutor or jury that you acted in self-defense or the the physical confrontation never happened at all you may well be convicted on it. I strongly suggest you hire a criminal defense lawyer to represent you on this for your best chance to minimize the impact of this on you. It’s going to cost you a lot more than what it would have cost to replace that bike. Indeed, that stolen bike might have even been covered by your homeowner or renter’s insurance.