What would you do?
I'd try to stay on their good side.
But seriously. I'd get them locked up. I don't want my life taken by another idiot in my family.
Depends on who they were, who they killed, and why they killed the person.
Have a few people I don't like meet them
I would probably turn them in to the police.
Beat them at their own game.
Oh great, destined to be fucked.