If you don't already have security cameras that watch your trucks I would highly recommend getting some immediately, if not sooner.
Even a trail cam, like hunters use, hidden away for temporary until you can get and install some better ones.
Punks like that are vindictive and I wouldn't put it past him to try something stupid when your not home, remember he knows your schedule, and how much work you have invested in your trucks, and he doesn't have a job so he has plenty of spare time.
I hope he doesn't try anything stupid but it is better to be safe than sorry.
My two bits, for what it's worth.