In my rpg when you kill someone you get a bounty on yourself unless they attacked you first or they had a bounty. Then when you kill someone with a bounty you get money.
A small portion of money was also stolen from you when you died, but when the guy was finally caught he was forced to pay some fees( and he couldn't use shops marked as a criminal )
So, pros and cons of killing
Pros: get sum cashes
somewhat exciting
Cons: lose sum cashes
gotta run from bounty hunters
cant use shops for a while
And even then I set up a system for town guards, etc.
So anyways, it can be okay to steal a small portion of money on death, but it has to be balanced out so people aren't just going on killing sprees instead of playing the rpg. We did have a few evildoers but they mostly hid in the mountains bothering people who came near and making occasional raids on nearby towns-- it was more organized than one guy just killing everything.
Also, VERY important, make sure that if you add some checks and balances, self defense is accounted for-- nothing pisses me off more than seeing an rpg where if you attack your attacker(and kill them) you get in trouble for fighting back. Its like those crappy dms where the admins kill everyone and tell you that your not supposed to kill the admins.