Officials say thieves are not only increasingly breaking into mailboxes, they're now attacking mail carriers.
On Tuesday, officials announced 10 arrests for mail crimes throughout the Bay Area, including one for attempted murder of a mail carrier.
"There is obviously a wide range of things that they are getting," said Ismail Ramsey, U.S. attorney for the Northern District of California. "Some with stolen mail, some with stolen credit cards and IDs. I can tell you regardless of the motivation, the result of these are that letter carriers who are just doing their job are not feeling safe and in many instances are threatened."
In many cases, Ramsey said thieves are attacking mail carriers to steal and illegally copy master keys that open banks of mailboxes or larger mail storage facilities.
"Unless this behavior stops, we will marshal the resources of my office to bring all violators to justice," Ramsey said.
Edward Fletcher, union president for the East Bay branch of letter carriers, said they have had 31 armed robberies or assaults on mail carriers since February.
"Our carriers are frightened to death," he said. "Some of them have gone out on post traumatic stress. Some of them have not returned to work. Letter carriers don’t wake up in the morning wondering if someone is going to stick a gun in their face. They are being hunted."
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Fletcher said in many cases the thieves are following carriers and holding them at gunpoint.
"We want results, and the community can help," Fletcher said. "It's your mail. This is your communities. If we all stand together, we can make a difference."
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To help encourage people to report the crimes, officials announced a $150,000 reward that leads to the arrest and conviction of more suspects.
"To any copycats or wannabes out there who might consider robbing a postal worker, I ask you to consider the years you will face in federal prison," said Rafael Nuñez, U.S. Postal Service San Francisco Division Inspector in Charge.