When insane people commit a crime they should be incarcerated. The victim should have justice. But, it seems that McAfee started going downhill years ago. Look how far he's gone. That could happen to anyone. He's just in the news because he was rich and has a recognizable name. If even the rich can have this happen to them, there is little hope that we can be truly effective at stopping others from having the same happen to them.
I do not believe the purpose of incarceration should ever be justice for the victim, it should be safety for other potential victims (either from the criminal, or from those who would see the crime go unpunished and decide they can do the same). That's the reason why we should put mentally insane criminals in mental institutions and not in jail, too; if everything works well, that should shield the lowest chance of more people being hurt.
If you want justice for the victim, punishing the perpetrator is not the best way to go about that. Making the criminal make reparations is a solution in some cases (notably not in murder).