Braintree police are searching for a high-tech identity thief, after a customer discovered a fake ATM card reader and a hidden camera at a Citizen’s Bank branch. Police responded Saturday to a call from the bank at 865 Washington St., where a man reported that while trying to remove his card from the card reader that allows access to the ATM vestibule, he had pulled off a fake scanner that had been placed on top of the real one, Police Chief Russell Jenkins said. The reader stored users’ credit card numbers. Jenkins said he did not believe that anyone’s identities had been compromised.Todd Feathers can be reached at email@example.com. Follow him on Twitter at @ToddFeathers.