I have a good idea for you which worked for me on a roleplay server. It's basically a "Cops and Robbers" version of hide-n-seek. The fun thing, is that you can slightly abuse your powers a little, and simultaneously having people voluteer to be punished. Weird, I know. But, let me explain:
First, you have the concept of KOS only allowed in certain zones. You create these zones with the server setting that disallows building in city limits. You must prevent people from building bases on top of loot spawns and such. But, this is also the boundry for KOS or not. So, if you can place a structure down, then you are in a "safe zone". Before you get triggered, realize there is still killing in safe zones. Accidents happen, or base defense against raiders is acceptable. If you are in the citiy limits where structures can NOT be placed, then KOS is allowed and legal because the players died fighting over resources, as they should. But, if you were outside the city boundry, and shot like a common deer, then this is the evidence police need determine if a death was justified, or flat out murder. It's an open and shut case. The guilty get sent to prison.
Second, when you're interrogating, or robbing someone. It's uncessary to make them strip or drop all their weapons. The problem is, this situation creates tension where players will shoot, instead of losing their best gear in a robbery. If your intention is role-play, ask the suspect to drop all their liquids, or food. Then, you choose the worst of the bunch, and take one item. Nobody will care about losing that 10% can of tuna. This is why the police should always, and only be, server admins. They can "abuse" their powers to spawn anything they want, as the city government provides the funds to provide law enforcement protection. So, since police can get anything, they don't need to take players gear. So, conduct premisis searches and suspect interrogations with a clear intention that you're not going to take anything of real value.
Third, along with the crime of murder, you also want to make having common items crimes. This ensures that no matter who you come across, it's almost garunteed they've broken some law and you can "let them off" with a warning, pay bail, or throw them in prison. What worked well for me, was making glue illegal. In a few days, you will literally have players scouring the map for glue and hoarding it. Why? So they can drink it right in front of you. Why would they do that? So they can be sent to prison.
Yes, that's right. Spawn in all the materials you need for a 7x7 supermax prison. You then hold prison events such as the popular "work release" program. You place 2 garden plots and give players 100 seeds to plant. After they grow, you get another prisoner to harvest. It doesn't matter that you never get any more food from this. The point is to just boss people around in prison. You'd be right to question why anyone would actually want to be arrested for glue drinking, and thrown in prison. But, you will literally have players lining up outside to get into prison. And, other times you will have someone attempting to break in to free a buddy, or attempting to break out.