I at no time labeled this man a criminal. I labeled him a threat. I said that, given the facts of the case, the only rationally and legally sound choice is to arrest him and charge him pending the results of his psychiatric evaluation. When he is (almost certainly) determined to be of unsound mind when the crime took place, we may proceed from there.
I have spent enough time in the company of psychiatrists and the mentally ill to know that mental illness does terrible things to the people who have it, and they often have no means of determining real from fantasy or right from wrong. But this man is not a diagnosed schizophrenic. He has no history of hallucinations or violent outbursts I'm aware of. Prior to the events of that flight, he was (strictly legally speaking) a sane human being with a long history of rational action as a flight crew member.
The police haven't locked this man up and thrown away the key. They're doing their jobs so the psychiatrists can do theirs - determining if this proud and respected career pilot now suffers from a psychosis that has heretofore gone unnoticed in his private and professional lives. That is not a judgement I want anybody except medical professionals to make. And until they do, the police and the prosecutors have a job to do.