So lets make him well/sane, go to trail, find him guilty, then deal out proper punishment. You have stated in other threads that even the insane make decisions (based on their reality). Yes, it is to bad he didn't get help before the shootings. He is still responsible for his actions.
The insane can sometimes make decisions - depends on the illness. But even if he can make decisions, his decisions may be inherently irrational, or based on a false reality.
I can make a decision that I have to put staples in my cat because I believe she is infested with aliens that are drawn to metals, and this will allow me to draw them out. If I believe that completely and totally, as a delusional person could, then my decision is justified in a delusional reality, but does that mean that I ought to be punished for animal cruelty?
Not really. It does mean that I should receive immediate and aggressive psychiatric help, as I would be a danger to others. It may also mean that I should not be permitted to own animals.
But does it mean I should do time? No. The decision I made was consistent with my perception. My perception just happened to be incorrect in the extreme to the point that I would not be capable of making rational decisions.
Delusional perception doesn't understand things like animal cruelty laws and physical harm to self or others. None of those things exist in a delusional reality, except in a delusional way.
They literally can't reason like you and I are right now. Their reasoning ability is cut off.
I read a case about a girl with severe schizophrenia who wanted to cut off her hands to prevent her from hitting people. She was obviously psychotic. Her wanting to perform that action would result in her death without immediate medical intervention.
But does that mean she is suicidal? No. Wanting to cut off her hands was her psychotically reasoned solution to the problem of hitting people.
Treating her as though she is suicidal is not going to help her. Her problem is not being suicidal. Her problem is psychosis. Treating her as though this is a behavioral problem will not help her. Her problem is not behavioral. Her problem is psychosis.
Likewise, punishing Loughner is not going to help him, or anyone else. His problem is not that he was a man on a vendetta. Even if it were, his inability to reason makes his actions irrelevant.
It is important that society be protected from violent people, mentally ill or not. But punishment is not a good reaction to mental illness. That assumes the psychotic actions are a behavioral problem. They are not, and treating them like one won't help the person. Helping the person reduces their violent potential, so it is in everyone's best interest to want to help him.
Psychiatric treatment could help him and make him less dangerous. Punishment will not.