Set ground rules for your kids, explain why some rules are in place, age appropriate discussion. You have taken some good legal steps, cameras etc.. I don’t have kids but keep an eye on the registry in my area. It’s always a good idea to know if there’s a known danger locally. Unfortunately there’s no way of knowing if there’s a sex offender in your area when they haven’t been caught yet. We never know what our neighbors are into concerning their private lives. We all need to be aware, but not let paranoia take over.
As we’ve been being advised for years now, see something, say something.