By Tim McNicholas

PARK RIDGE, Ill. (CBS) — A batch of mail has been stolen from collection boxes outside the Park Ridge post office again, this time after thieves pried them open overnight.

Park Ridge police said an officer was conducting a “premise check” of the post office around 12:30 a.m. Monday, and spotted three mail collection boxes outside the building had been pried open, and the mail inside had been stolen.

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All three collection boxes recently had been replaced, according to police.

One after another on Monday, Postal Service customers drove up to the blue boxes – only to find them out of service.

“It’s terrible,” said Roger Bowman.

“I just saw police tape and I was like, what?” said Domenico Giannini.

“I was really surprised to see the yellow tape like that,” said Jodee Hartjen.

The last time mail had been collected from the three boxes was Saturday afternoon. Police said the theft happened sometime between 4:30 p.m. Sunday evening and midnight.

If you dropped off mail there at that time, you should call the police, and if it was a check, you should cancel it.

Police also warned anyone who had dropped off any mail containing financial payments or personal information to take steps to protect themselves against fraud — including notifying their bank to cancel any checks, and using an identity theft protection service.

Anyone who believes they are a victim of mail theft should contact U.S. Postal Inspection Service at www.uspis.gov/report, or make a report with the Park Ridge Police Department who will then forward the report to the U.S. Postal Inspectors Office.

Park Ridge Police said they also have met with the Park Ridge Postmaster regarding security concerns at the post office, and have offered their assistance with the investigation.

Earlier this fall, CBS 2 uncovered a pattern of mail theft and check fraud at the Park Ridge post office.

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Court records say a Dolton man somehow got hold of a postal key and used it to steal from a blue mailbox outside the Park Ridge Post Office. He was arrested in September, but police said they are still investigating.

And even that arrest was not enough to stop the crimes.

“I thought that was resolved. I thought that they caught who was doing that,” said Hartjen. “So it’s very frustrating to come here and very sad to see something like that.”

“It’s crazy how people put so much time and effort in doing the wrong things instead of the right things,” said Giannini.

Back in September, we reported not just on the thefts, but the rusty condition of the mailboxes in Park Ridge that left letters exposed to the elements and whatever else. The postal service replaced the boxes after that report.

Now, thanks to the thief, the blue boxes will have to be repaired or replaced again.

Meantime, police in nearby Lincolnwood also are investigating a pattern of mail theft and check fraud involving the village’s post office.

There are more than a dozen cases of people who say a fraudster tampered with their checks after they mailed them. CBS 2’s Tim McNicholas has learned it has also caught the attention of federal investigators.

The Lincolnwood Police Department has taken 17 other reports over the past year, all from people who had their checks altered after mailing them. The department said it is working with U.S. postal inspectors to investigate the pattern.

The U.S. Postal Inspection Service will not say whether there is any connection between the Park Ridge case and the one in Lincolnwood.

A spokesperson said postal inspectors are actively investigating mail theft in the Chicago area.

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Investigators said they did have surveillance footage of some of the past thefts. As for whether this one was caught on camera, investigators would not answer that question.

Tim McNicholas