My ipad was stolen and I don't have the serial

It was stolen by the cleaning staff at a motel. The police need the serial # to file the report. I don't have the box or the receipt and the day before it was taken I wiped it clean so I could start using it for a new job opportunity. If anyone can help me with this I would be very grateful & would not have a problem sending you a $50.00 Amazon gift card.