The theft happened on Wednesday at a fitness center in Lower Southampton Township.
Police say the suspect entered through a handicapped entrance then went into a locker room and stole a set of car keys.
The man was then caught on camera using the keyless entry system to rummage through the victim's vehicle.
A wallet, include retired law enforcement credentials, access devices and other identification, was stolen.
Credit cards from that wallet were used within 30 minutes of the theft at the Best Buy store in Willow Grove.
Anyone who can identify the man is asked to contact Lower Southampton Township Police at 215-357-1235 ext. 339.