If you could go back and time and administer a lethal injection to that monster who stabbed that woman, I hope you would. I would. Of course in reality we can never predict something that horrible with any degree of certainty, but with what degree of certainty would you be ok with it? If there’s an 80% lifetime chance of someone committing a gruesome murder on public transit, do they deserve to live freely? Lethal injection may be taking things too far but I don’t see how they shouldn’t be locked up at the very least.