"It's very well known that the death penalty is NOT a deterrent; Hence it did not deter this guy nor his sidekick (!)." -Janq
No one knows or is able to tell anyone how often the death penalty has or has not been a deterrent to anyone. All we know is what has been said about it by some____not all____ criminals, and some____not all____ "experts". We don't know!
That it did not "deter this guy nor his sidekick (!)." means only that - it did not deter this guy nor his sidekick (!). . . it does not mean it will not deter someone else. It's not 'all-or-nothing'. If it deters anyone it has deterrent value - and you'll never know about it.

