Motion activated lights can deter people as well, they start messing around and then a light turns on and spooks them. Doesn't always work and won't work if they are determined, but maybe the light coming on will alert you that there is someone out there as well.
Maybe even a camera like a Ring brand where it records video and sends you an alert to your phone. So I would pair that with the motion lights, the lights come on so the camera can get a good view and it sends you the video to your phone. At the least if you can get good footage of them you can send it to the police.
Also, make sure your yard is clearly marked No Trespassing. If it isn't then there probably isn't much you can do about them being on your property as stupid as that is.