The entire set of circumstances would have to be taken into consideration including the relevant laws of your state. If he were making such a threat and you "subdued" him for the police and made a private person's arrest for the threats, then you would probably be okay, but it all depends on the entirety of the circumstances. If you had started by threatening HIM, and he did that to scare you off to protect himself, that would backfire on you.
It all depends.
- Carl

