If he were a man whose "word was his bond" he needs to be in jail awaiting a comprehensive Psych or other exams. In his tape he made pretty concrete threats he just did not name the folks he was going to shoot.
If he is just a big mouth blowhard maybe then they can give him some slack but closely watch him anyway because sometimes even these types will act.
This is just a matter of government protecting others from the unbalanced, young, strong, and reckless.
“Food for thought is no substitute for the real thing”