I am sure the concensus will be " f*** him " " hang him high " but I am not convinced it really acheives a lot at the end of the day. I find it tragic and horrendous the actions he took but also tragic that society and what happened to him made him do it. No one is born evil imo and life's events dictate actions. Fortunately only a tiny fraction of people take out their frustrations in the manner he did but it is obvious he is very ill. So the question is, if someone is very very ill and does what he did, what does society do ?
Put him to sleep.