Ongoing mail theft in Colorado city the result of United States Postal Service master key stolen years ago

Handwritten notes about where Vanessa Ewing's missing package went were the key to unlocking a much bigger problem within her Denver area neighborhood.

"This is just huge. My understanding is it's hundreds, maybe thousands of people that this is the case and I wasn't even told that my mail was being taken anymore, right? I just happened to find out because I asked what happened," Ewing said.

After not receiving a package that the United States Postal Service marked as delivered, she learned the arrow key used by the mail carrier to access their cluster of mailboxes and several more in the area had been stolen roughly two years ago.

"I guess I wonder how much mail I've missed over the last couple of years," Ewing said. "People come whenever they feel like it to steal from the mailboxes."

She wasn't the only one who didn't know and started alerting her neighbors.

"None of us were told about it," one neighbor said.

"I know," Ewing responded.

"You'd think the postmaster would put a note in everybody's thing?" the neighbor added.

"You would think, that would be nice," Ewing laughed.

Now that she knows what the problem is, she's quickly learning that getting something done about it may take just as long.

The HOA asked about replacing the locks on their own but it's expensive and it's not their property. They also reported the crime to local police but were told it was a federal crime.

Complaints made to the U.S. Postal Inspection Service led to a spokesperson for Frontier Management telling CBS News Colorado that they have had little response, despite dealing with theft at multiple properties it operates.

When CBS News Colorado reached out to the postal inspector in the Denver region with questions, she confirmed there was a case.

"We do have an active investigation related to mail theft using stolen/counterfeit mail keys in that area. Unfortunately, I can't comment on the case until it is resolved," U.S. Postal Inspector Melissa S. Atkin said.

Ewing didn't just reach out to CBS News Colorado; she also called her congresswoman for help, prompting a direct call back from the United States Postal Service Consumer Affairs Department and received a detailed voicemail about what is and isn't happening.

"I wanted to let you know there had been an ongoing and active investigation by the United States Postal Inspection Service as to the arrow keys you referenced were stolen," the representative said, in part. "The postal inspection service has updated us stating they have made over 60 arrests in that case but have not commented on whether or not they have closed or concluded the investigation itself."

While USPS did not want to go on camera to discuss fixing the issue, it's confirmed from that voicemail that after all this time, the post office is working to change those locks along with tens of thousands of others across the country; a change that comes with its own challenges.

"Currently those locks are on backorder. They are beginning to trickle into the Denver area, I believe we received about 3,200 of them, but we still have another 1,100 or, I'm sorry, 11,000 left to go as they come in, they will begin updating all the boxes," the representative said. "Yours are primed. I did see a work order from your office."

The push for the use of an electronic key is partly in response to concerns from mail carriers about safety and a rise in attacks by those looking to steal the keys and other mail.

For postal carriers, the change can't come soon enough, for Ewing it's already far too late.

"I would've loved to have known," she said, "So, I've just spent a bunch of money for things I'm not going to get back and this time of year everyone starts getting their taxes and things that's scary that's a lot of that's big information for a thief to have," Ewing said.

CBS News Colorado asked the U.S. Postal Service for the total number of boxes that have had their locks changed over to the new system and did not yet receive a response. 

The postal inspector also did not have any information on those 60 arrests mentioned in the voicemail and could not comment on any arrests.