It's possible, though I think it more likely this kid could be of use to us. Think of it in this way, maybe he has some brain chemical imbalance or some genetic cue that made him bat**** crazy. Now if you just kill him or abandon him to a prison system you never find out much more, but if you study him maybe you actually save some group of brothers in the future?
I look at it in this way. Say some dude got an incurable disease that's contagious. Now you can't let that person just roam the streets cause others would get hurt. But just killing him is unfair (cause it wasn't his fault he was born screwed up) and stupid (cause you'll never learn more about the disease). The smart and right thing to do is to isolate and study and hopefully learn enough to find some type of a cure. Mental diseases are really not different in terms of theory and practice.
I'm not someone that thinks all evil isn't the fault of the perp, but in this case it really doesn't seem to be. The kid killed his brother for no reason, he said it felt like satisfying his hunger. He has no history of being anything other than a good kid. He seemed happy after the act with no remorse, and then later he just turned himself in. These are the actions of the insane not a criminal. Criminals gain something from their crime, they feel somewhat guilty or at least paranoid after the act and they try to avoid being caught.