William Spencer, 33, of Buffalo Township was arrested early Wednesday morning while on the job at Giant Eagle in Buffalo Township.
A search turned up an assortment of drug contraband in his pockets.
District Judge Sue Haggerty arraigned Spencer on a felony charge of retail theft and three misdemeanor counts of possession of drug paraphernalia.
He was placed in the Butler County Prison on $10,000 bail following arraignment.
The loss prevention manager told police that the store had suspected the defendant of stealing and had “been watching him for the past couple of nights,”
Police said Spencer’s duties are to clean and maintain the store’s floors after closing time.
He is accused of trying to take $4,440 in merchandise including vitamins, medicine, beer steins and water filters.
Police said when they searched Spencer they found an empty stamp bag of suspected heroin, a hypodermic needle and a spoon with suspected drug residue on it.