Yes. 12 is mature enough. Anything that happened not by accident but an actual planning should be enough reason to put a person in jail. Even a 10 year old know what a murder is. Just my two cent.
life, meaning life - captive up until their natural death, or a swift injection.
Honestly? I don't think prisons should be about punishment. I think they should be about rehabilitation. That is not to say though that it should go as far as being comfortable to the point of being homely. <br />
Giving time sentences to people doesn't make sense in my mind. Some people could get life in prison, but be completely rehabilitated by 20 years. Someone else could get 30 years in prison, and come out just to go straight back into crime. <br />
They should have multiple teams of psychologists who assess each prisoner, and decide if they are 'cured' as it were. <br />
Then they should be given a chance, but continue to be supervised and supported. <br />
We do have a version of this already, but we rely more on punishment and time than we do rehabilitation. <br />
Looking at the individual case you present, I think 65 years is completely wrong, at such a young age, opinions can be changed, information taught and morals built. You would not need anywhere near 65 years to rehabilitate someone.