[Tyhm]

Suggestions:
Yes, cop who catches the most wins, and robber who gets caught last/the least wins.
Maybe there should be a jail on the field, a robber can pick the lock if noone catches him, and he can get -1 capture when he lets all the other robbers out?
Maybe it should be like Classic CTF, the police have blue belts/shoes/sleeves and the robbers have red belts? They can set it back outside, but they can't change their belt color during the game. It's easy to have it detect your colors, too!
Maybe use stunning rules: if(playerdies){ playerhearts=1;freezeplayer 5;}