Hood lock suggestions

Unfortunately, oftentimes the threat of physical violence (and, if needed, warning shots) are a better deterrent to criminal activity than the police and court systems provide. But, when push comes to shove I personally like non lethal techniques, like a large arm brace slingshot with big steel rollers or balls out of bearings and rock salt ammunition...
My brother-in-law has one of those. That thing has wicked power, but aiming it seems to be a challenge.