I strongly believe that those who've individually been served specific due process, and been convicted (or committed) for a violent crime or dire threat to others, would be the only folks who we have any right to jump on. They're still citizens, still in full possession of their basic rights, and unless the sentencing removes them from society for purposes of protecting society from that danger, it's not deemed there's sufficient danger by said person.
Fact is, the average person can find weaponry most anywhere. And anyone just the least bit enterprising can tap into the 'black' market and obtain weaponry. About all it takes, if truly dangerously violent, is to rob someone or break into a home or car. Do that, and you stand a very good chance of getting re-armed rapidly. No law's gonna stop that from happening.
That's about it. Due process. And, at least IMO, after due process and the related sentence term has expired, I can find no legitimate reason for stripping a person of his/her preexisting rights either. If you get incarcerated or involuntarily committed for cause (due to violent threat), for the term you're there you are kept securely (to ensure the sentence is carried out). Post-term, you're free. Literally. No parole crap. No conditions. You've paid your debt. And, no, I disbelieve that ongoing stripping of a person's inherent inborn rights constitutes part of the sentencing due process can effect. You want a person gone permanently, for cause? Execution or expulsion from the country. You want a person temporarily segregated? Segregate, temporarily. That person isn't a direct violent threat to others? Then IMO incarceration or involuntary commitment specifically for cause of violent threat is hardly warranted, and hence no stripping of such rights should go with that.
Yeah, but how do you go after folks who are a threat but who've yet to be caught or committed or incarcerated? That's just it ... such people are not yet dire threats or criminals, hence they have full retention of every single right and privilege you and I do. Until due process is served, for cause.
JMO.