I'm looking for a person on my bike

First, they stole my truck. Stealing a man's truck is like kicking his dog. Or stealing his dog.
Now just a few weeks later, they steal my bike (mountain bike, the kind you push with pedals). It stands to reason that.. some things just don't.. they ought not a' done.. anyhow I'm looking for a person on a big downhiller. It's an 18" Giant Reign X2 (grey/blue) with a dual crown Rock Shox 155-200 mm front fork. There aren't many big downhill bikes in Chicago (it's flat, no mountains), so it's not that difficult to spot one.