Try to develop your rdm and nlr explanation a bit more since right now they are pretty basic. The same goes for how you would handle the situation. For starters as a mod you can't ban so that wouldn't be possible, also
If the reason was that player x was a cop and player y was wanted i would just explain to player x that its not rdm.
It is rdm unless the cop made an attempt to arrest/kill the wanted player.
Goodluck!