Dangerously crazy people should be locked up BEFORE they kill.
They need a proper diagnosis and treatment first. Supervision, support, sympathy.............
Time and time again we hear that they had the diagnosis. That reports were written. That supervision was tried and failed, repeatedly. That they were given all the support and it was useless. ect ect ect
But that no one is willing or has the authority to actually lock up someone who is a danger.