Here's how to handle this:
1. Do whatever you need to do to find out which guy did it.
2. Gather a couple buddies to help get back at him.
3. You three grab him and toss him in the trunk of his car.
4. Tell him through the trunk door that your going to park his car on the train tracks and watch him die for fucking with you. Sound very serious and act like you're crazy and pissed enough to really do it.
5. Drive his car down to the tracks, then park it off to the side NEXT to the tracks.
6. At this point you can do some more talking and scare him some more now that he knows you're there.
7. Kick back and wait for the train to come by. He's in the trunk and can't see, but he can hear it coming towards him even though it's not actually on the tracks.
8. (optional for added effect) You or one of your buddies head down the direction the train is coming from, and see if they can signal the conductor to lay into the train whistle so the thief can hear it.
9. Once the train passes, pop the trunk open, point and laugh as he's probably in tears and laying in a pool of his own feces (this is why you use HIS car).
You probably won't hear from this person again.