It's super important that you have a clear and concrete end-goal for the story.

You need set this up in the first act, and resolve it in the final act. The reader (and the hero) needs to know what the hero has to do, and what will indicate that he has achieved or failed - the central question of the story.

Obviously, in a story with a single antagonist, this is pretty easy. You set it up that the hero must defeat the antagonist. The reader knows that this is the goal, and that the book will end either with the hero succeeding or failing at that goal. There is a clear end-state.

If you have multiple smaller antagonists, you still need a concrete end goal, otherwise your story will just seem like a succession of incidents with an arbitrary end point.

So you need to think about how you can show that he has succeeded or failed at "reducing crime and helping people". How will he know if he has achieved his goal? How will the reader know?

For example (and this is just off the top of my head), you could start with the villagers annual festival being ruined by the local criminals, and the hero vowing to put a stop to crime in the area. Then by the end the annual festival is held and it all goes smoothly. The hero had a clear goal, and we see from the end that he achieved it.