i need the serial number of a macbook that i had repaired years ago

My 2008 macbopok pro was stolen out of my truck 2 nights ago. The detective on the case told me to acquire to serial number to assist in the investigation. Its my belief that the police may have recovered my laptop from the suspect and are waiting for me to identify it with a serial number. I had this laptop repaired in the early 2010's. i was told to contact apple support in order to acquire this information.