Ok, so update: I spoke to a police officer in my school who told me that the police "probably won't do anything" about this person. When I questioned why, she said it was because there was no damage to me or my bike and that there were no witnesses to back me up. I told her I found this incident no different than someone pointing a gun at me and threatening to fire. I think in larger cities, the cops don't take these "bike things" very seriously.

I had posted earlier that I narrowly avoided an attacker who did $55 damage to my bike using only his feet. This same guy knocked another girl unconscious, and she reported this all to the police. THEY DID ABSOLUTEY NOTHING. They ended up giving her bike away, too. She went to the precinct to retrieve it and was told it was "somewhere on Long Island" and they "couldn't trace it," which basically translated into: "I gave it away." And yes, cities can be a "small world," b/c it turned out that this girl is a friend's roomate! She's traumatized and won't ride her bike anymore.