Night of the reverse burglar

My neighbor woke me up two nights ago by pounding on my front door. "Someone was trying to steal your bikes," he said.

I was confused, because I only had one bike stored outside -- OR SO I THOUGHT.

I put some shorts on and walked to my back porch. I glanced at where my bike had been and saw only my back wheel, locked to the water heater.

"Bummer," I thought at first, but then I looked at my wood chip garden and saw my bike; it was dark, so I could barely make out the shape of the bike, but I realized that something was wrong with it. It looked like the burglar had mangled my bike in an attempt to steal it.

I called Lindell (my neighbor), who actually had thrwarted the robbery-in-progress, and he came out to investigate the damage. It turns out that the reason Lindell thought I had multiple bikes was that the burglar had actually LEFT HIS OWN BIKE.

Yes, the Kingpin of Crime (as Baby later dubbed him) got scared and dropped his bike, which got tangled up in mine. It took me about 30 minutes to get the bikes apart, but now I have a really crappy mountain bike! Anybody have any ideas for it?

My first thought was to put a "FREE BIKE" sign on it and leave it on a street corner, but I'm sure there's something better for my newfound acquisition than that. I have also considered making a bicycle out of dynamite and trying to lure the thief back, but at this point I mainly feel sorry for the guy.