Couple of things I'd do to end the situation, safely and without confrontation:
1. Reverse your habit of locking the cars via remote. Do it when you first go out, and don't turn off the light right away when you go in, or have it on a timer switch that you can set to turn off at different times. I'd also leave a light on in different rooms near that porch, also on random timers to make it seem someone is still awake.
2. Put a motion detector in your yard that pops on the light and possibly triggers a video recording system.
3. Post a sign on your gate that states your property is being monitored by closed circuit TV.
4. Assuming your fence is high enough to prevent him just easily jumping over, I'd also put the electronic lock on the gate that can be turned on and off by remote or from a switch in the house.
5. Make your habits unpredictable and as difficult as possible for him to discern patterns in and he should be discouraged from coming around.
If none of that works, then I'm all for escalating to the "pranks" like setting up a turd cigar (my maltese leaves them all over the yard
) or capgun caps planted in the cigars. If there's any legal implication, you at least can show all the legal things you attempted before going to the extremes.
