Also don't show up in the car that he stole it off of. Call the cops in advance and tell them you want to check out this bike as a lead or a potential replacement. I bet they'll be willing to back you up on your first visit if the frame size is the same.
Also, get property insurance. I pay $30 each month for Renter's and have $40k coverage and a $250 deductible for any theft, fire, flood, etc.
When my older Bianchi was stolen in Fort Collins the insurance company gave me $750 to reaplace it.