Ok I'm gonna make it nice and simple for all you idiots out there. This is just an example, you could kill them in any way I guess.
Your in a room with a button. If you push the button, someone who you have never met dies and you aren't caught/don't go to nonexistant hell. The person who died dies by what appears to be natural causes, family mourns, etc. If you don't push the button, nothing happens.
Also the person who died could be anywhere from the next Riddler to a new born child.