Remember the maniac in Canada who killed another passenger and then beheaded him. A recent news report says that during his court trial he offered a plea of not guilty.
Furthermore his lawyers are pushing a line of defense that says that he is mentally ill and for that reason he should be found not guilty.
It makes me wonder a bit about how many mentally ill people are walking around. How many are there floating through life and how many are dangerous. You just never know who you are going to encounter.