Elaborating on from my previous post, I know a thing or two about police RP in gmod, holding a high rank in probably the most in-depth police department project over in the PLPD.
This does not sound anything close to good police RP. Crooked cops are typically banned in these types of organisations because if they were allowed people would tend towards them over the other jobs and they would be abused (people going cop to release their friends, etc.) Overall this would completely ruin and "police RP" you may have.
In addition, no police RP can be accomplished with the short jail times that are on the server.
Capital punishment? Bad idea. People would just get themselves executed because being killed has no long term repercussions for the player.