The Cop works for the KVN fans. They collect gold so other KVNs can have it. The petrosyans have to deny the Money and Wood before the cop takes it. The cop can also build some sort of wall that protects KVNs from getting hooked costs 100 gold.

Either petro or KVN you can not take it, ONLY the cops can but ONLY the petrosyans can deny them. KVN fans can do nothing about it but just hope the petro doesnt deny and the cop arrives faster.