Considering that after his treatment he is in a better state of mind, there is no reason for him to go to jail. It is not his fault he killed his daughter. It is not his fault he never learnt to properly deal with his feelings. A person's actions is never their own fault. The only reason this man should go to jail is if there was still a chance he would cause harm to others.

First getting upset over anything does not give one the right to kill anyone. Second, getting upset to that degree means that, that man never intended to look at his daughter's point of view which could be because of two reasons, either he's not intelligent enough or he's a dictator, either way, he has low intelligence. Because of that he does not see his daughter as a person having individual rights. He sees only his point of view and justifies anything because of that. The man is NOT mentally ill but can get away with murder BECAUSE of that, by taking refuge under it. Our justice system endorses it. My justice for a man like that would be to place him with people with even lower intelligence than him and them having power over him.

there is no guarentee that he has a real mental illness. anger problems arent considered "true" mental illnesses as much as they are just a flare of emotion. i cant sit there and use emotions as a way to get out of killing one of my family memebers. i cant say that i was extremely sad leading me to take the life of lets say, my brother. had the man have a real illness, recieving help isnt fixing the problem. mental issues dont go away with treatment they just go into hybernation. you never know when something you do will trigger that and fling him into his rage allowing him to possibly take another life. at the very least, justice would be keeping him in some sort of psychward.

every action bares a consequence and people must be held accountable no matter what the circumstances are.