A radical New Testament approach would be to require former murderers to show atonement by saving lives, even at their own risk.
But again if the popular attitude were such as to support that, families probably would be already teaching young boys to do constructive things, rather than being aimless goons like this. And dealing with murder would be a much rarer task.
Since the victims are most likely democrats, I hope some local poll watcher checks the checklist before the next election to see that the victims are removed so they can’t “vote”, as dead rats often do.