Dude you still don't understand the issue, it's not illegal to fantasize about killing someone, you can't put someone in prison for fantasizing, which means the guy will be out on the street and maybe want to murder the person that was responsible for him ending up in a police investigation. Do you think the police will give some one around the clock protection?
And no a psychiatrist is not an expert on when to call the police or when not to, they are mandated to do it if they SUSPECT a serious crime, it's the law otherwise they will lose their license to practice.
Jesus fucking Christ
Dude how many people die everyday because their abusive SO kills them, even though they have been in contact with authorities? Happens everyday, everyday some dies because the cops can't do shit.
What you don't understand is: I'm not saying don't call the cops, what I'm saying is you are saying stupid fucking shit, that isn't help full at all. YOU don't know his reality, he obviously don't want to involve polis, because he's afraid, you get it? It's not about society, it's about him. A common trait with serial killers is that they lack the feeling of sympathy, are you a serial killer. Do you have hard feeling what others might be feeling, and hard time understanding why they don't want to involve the police? Why is that?