We need to learn from this. If someone goes to an authority and says that he is going to hurt someone, they need to be bound by law to check that person into the hospital and find out what is wrong. It’s nice to say put him in jail or execute him. Overtly mentally ill people do not belong in prison. That being said, he should not be let out for the rest of his life.
There was a Quincy M.E. show that described what people should get: “Insane, But Guilty.”
It used to be called mental institutions. Insane folk need to be set apart from general society(for their own safety and the safety of society). No hatred or prejudice...but they are too dangerous to themselves and others. Until we can find out why mental disease happens and how to control it.
The weak, and inadequate societal response to this human issue invites more innocent mayhem and death.