How to Stop Neighboring Tenants from Trespassing

I live next to a subsidized apartment building and have had problems with the tenants for years. The landlord has told his tenants to stay off of my land and to not throw garbage on my side of the fence, but that's been pretty much useless. The police told me to install security cameras, so I did. The response of some of the tenants is to harass me. I'm also seeing weird things, like large numbers of people who have suddenly decided to use my driveway as a temporary place to stop a car or to turn around, even though that almost never happened before. How do I get this to stop?

If your camera covers the driveway, and it's the same people over and over again, show your video to the police and see if they believe that it merits investigation or might constitute trespass or harassment under the full facts. If the camera shows acts of harassment, you can show those to the police, as well.

The landlord's duty to turn his tenants into good neighbors is negligible, and the police aren't likely to do much without evidence of harassment by an identifiable person or group of people.