There is a time worn, essential way to eliminate the sex drive of domesticated male mammals and it ought to be used on these beasts. So much cheaper than incarceration. Let the eunuch walk among his neighbors, fat and balding after his orchiectomy, as an example to other violent teenagers coming along. Let him toil and pay taxes but not reproduce or lounge in jail. Who knows? We might be able to breed it out of mankind. If not genetically, then by stopping the apple from falling off the tree; i.e. gentling the violent daddy. We all know there is a cycle of violence.
I’m not convinced that would fix all of these people. They might not commit the same sort of crimes, but they might still commit violent acts. I’m not willing to take the chance (altho I”m not opposed to neutering them as well). I want them locked away from the public.