Someone may be deemed a threat to themselves or others, yet it is highly unlikely that they remain in that state for very long.
The VT shooter was hospitalized ONE YEAR prior to his crime. Hannity suggested that the psychiatrist failed because he released the man. The problem with that reasoning is that at the time the decision was made, he probably (as evidenced by historical accounts) was NOT a threat at that time.
Armchair retrospective quarterbacking has never won a game.
Some people go through a mental health crisis ONCE in their lifetime (more likely MOST of us), yet we are productive for the rest of our lives.
Mental health is not separate from physical health. Some people with serious illnesses behave in "crazy" ways until they are healed. Do we restrict their freedom as well?
This truly is a slippery slope issue.