Attacks on letter carriers, like the ones caught on camera in Peabody and Melrose, are motivated by the "Arrow Key" that can access the big blue mailboxes. The USPS is replacing those keys with ...

Arrow keys are a universal key that fits a variety of mailboxes. USPS is working on replacing those keys with a new digital key. Johnsten said the new keys are making the biggest difference.

By using stolen USPS master keys — also called “arrow” or “universal” keys — crooks are able to unlock multiple mailboxes at once. “Yeah, not great. Not great at all,” said Todd ...