Bicycle detail

I was attending a play at the Curran Theater in San Francisco, and had locked my bike to a parking meter on the sidewalk out front. Sometime between 1:45-4:30pm, while I was in the theater, my bike was stolen. I came out to find my lock and helmet sitting intact around the base of the parking meter, with the bike gone. I had just purchased it off of craigslist a week ago and had forgotten to write down the serial number.