Actually, this makes me think... Is there any law against watching gun owners closely and holding them to the highest standards of accountability? If you own a gun and threaten violence against someone, even if the threats don't explicitly involve weapons, it should be an instant trip to the psych ward for assessment as well as temporary confiscation of your firearms until you've been shown not to pose any realistic threat. Should be the same for any kind of misdemeanor- if you want to own a gun, you should be expected and forced to conform to the highest standards of nonviolent, lawful public behaviour, and any threats you make in private should be taken with utmost seriousness by anyone who overhears you, as should their eyewitness testimony to doctors and police after overhearing said threats.
There should be responsibility costs imposed on anyone who wants to walk down the street with the privileged ability to end anyone else's life on a dime, just for looking at them the wrong way or cutting them off in traffic.