Why, everyone should be free to kill whomever they feel may have wronged them - who needs evidence, the police or the court system?
No, they should only be free to kill those who are guilty of capital crimes and not executed by the state.
We have no idea if this guy is even guilty. who the heck knows what happened.
NOW , if in fact he was found guilty I’d say let the dad have an hour alone with the bastard and give him a bat and a welding torch.