Crockett stole $825 from a safe inside Pat's Café in the city's Frankford section during a police investigation in the summer of 2010.
Crockett was on duty at the time and the theft was caught on videotape.
The case unfolded when two officers were responding to a report of a burglar alarm at auto shop located behind the café. The alarm turned out to be unfounded.
At 4:25 a.m., the surveillance video shows the two Philadelphia police officers peering through the windows of Pat's Café. Then, they go in through a cellar door which was apparently unlocked. They appear to have gotten into the bar through a trap door in the floor. A third officer can be seen joining them later.
The three officers are then seen in the video staying in the bar for about 30 to 40 minutes, drinking what Police Commissioner Charles Ramsey insists were non-alcoholic beverages.
Ramsey said the officers were inside looking for a possible prowler. FOP President John McNesby said at the time that the officers were looking for the owner's phone number to contact him about the possible prowler.
Then, while two of the officers have their backs turned, a third officer, who police identify as Crockett, goes into a safe and pulls out what appears to be wads of cash, stuffing it on his person. About $825 was taken, investigators said.
Crockett will be sentenced in January.
Pat's café is the same place where Officer Gary Skerski was shot to death in 2006 while trying to stop a robbery.
