for forensic evidence, broken glass along the window sill should do the trick. obviously this guy is one of the close neighbors and knows who you all are, your vehicles and what they sound like. this guy thinks he is a predator and knows all the angles. you need to outsmart him. try spending the afternoon with the girls. when it is dark, have one of them dress in your clothes and drive your truck away. you wait with the wasp spray, 12ga, whatever (keeping the broken glass on the window sill) and catch him "red handed".
I don't have any guns, but I do like this idea.