Police have been investigating a string of thefts in which the suspects smash open machines with sledgehammers. PHILADELPHIA - Three suspects are in custody in connection with a series of thefts from local convenience stores in which sledgehammers were used to break open game machines, sources tell FOX 29.FOX 29's Dave Schratweiser reports the suspects were tracked down by investigators Thursday night in an undercover sting operation.Sources say the suspects are facing charges in at least two of the thefts, but they may be linked to dozens of similar incidents.Money and a sledgehammer were recovered Thursday night, according to sources.