The fact that someone murdered someone is still a crime regardless of whether the incident was recorded or not.
so if killer kills your gf/wife and you kill him in return,
you go to jail for life or deathrow.
in moral view you did the right thing.
in your precious crime law youre the only one guilty here
no matter what was the cause and you will suffer and/or die.
do you still like your precious crime "stand point" ?