"You just don't expect to see someone coming in from the dog door!" Heather Berg said.

Her home was broken into in mid-October.

Berg stepped away one afternoon while her kids were at school so she could run some errands.

"When I came home, I unlocked the front door and realized that the big screen TV was missing and our things had been rifled through," Berg said.

The mess led Berg to the kitchen and to the back door. That's where she discovered a burglar had kicked in her doggy door. She doesn't have dogs, but has cats which use the doggy door.

"I think it was just a random act," she said.

It seemed that way at first, until Berg heard about the other neighbors whose homes were also broken into.

The closest home was a block away, at the corner of 31st and Julian Avenue. It was a very similar situation where someone got in through the back doggy door and got away with hundreds of dollars worth of goods.

In Berg's case, the thief or thieves got away with her computer and some other electronics.

"And took everything that they took from here and put it in a duffle bag and essentially went out the back [door]," Berg said.

Luckily, they couldn't lift the TV over backyard fence, so it was saved.

Police say this isn't an unusual crime and everyone should be aware of the potential danger.

"Almost think like a thief. If I was going to break into my own home, what would I do? How am I vulnerable?" Sonny Jackson with the Denver Police Department said.

Police say it's important to purchase extra locks instead of relying on the one that comes with your doggy door.