The United States Postal Service says thieves are getting into mailboxes using counterfeit keys to steal tax returns.

In a video obtained exclusively by NBC 6, U.S. postal inspectors said William Gomez is seen inside a Coral Gables apartment building using an unauthorized key to gain access to the mailboxes.

Gomez is seen opening multiple boxes at a time–sifting through the mail. Federal officials believe he also went into a building in Miami Beach and Sunny Isles.

Officials say Miguel Cadierno is Gomez’s accomplice as he’s also seen in surveillance video opening numerous mailboxes. He appears to spot the camera–comes right up to it–and then returns to the boxes. Cadierno also opened the mailbox with the fake key, inspectors said.

Thieves Targeting South Florida Mailboxes for Tax Refunds