Authorities across Western Washington are warning real estate agents and homeowners about recent thefts targeting open houses.

In this red-hot real estate market, they say it's happening more and more often.

On October 6, Arlington police say a man and woman went to a brokers-only open house and posed as real estate agents. When asked for identification, police say the pair told the agent in charge of the open house that they were out of business cards.

Once inside the home, a surveillance camera in a bedroom caught the thieves on camera. The woman acts as a lookout as the man rummages through a jewelry box on a dresser. He can be seen putting several necklaces into his pocket.

Police say more than $800 worth of jewelry was taken from the home. The homeowner supplied detectives with the surveillance video, and it quickly proved crucial to the case.

Arlington Police were able to work with detectives from King County, Kitsap County, Mercer Island, and Renton to identify the man seen in the video. He's now in custody in King County and charges are pending. Police are still trying to locate his female accomplice.

It's believed the man may be behind similar open house thefts in Mercer Island, Poulsbo, Port Orchard, and King County. The man allegedly told detectives he committed the crimes to support his heroin addiction. Detectives say he also had heroin on him at the time of his arrest.

But it's not just one person or even one group of people targeting open houses.

"Unfortunately, it's all too common. We hear about these happening more and more," said Sam DeBord, who is the president of the Seattle/King County Association of Realtors.

A similar theft took place on October 1 at a home in Covington, and the thieves in that case were also caught on-camera.

Surveillance video shows a man and woman take their shoes off at the front door before entering the home and pretending to be potential homebuyers. The homeowner told KING 5 the thieves gave the real estate fake names, addresses, and phone numbers.

The King County Sheriff's Office says they've arrested a woman connected to that case. They are still searching for the man she was working with.

DeBord says it's something that homeowners and real estate agents must be vigilant about.

"I think the most important thing is identifying people who are coming into a home," he said. "Verifying who those folks are. Whether that's getting a picture of their ID and emailing it into the office, whether that's getting people to sign in at an open house. Just letting folks know an open house is not a free for all."

He said homeowners should have their real estate agent carefully review their home before an open house, to help identify items that should be removed from the house.

"Not just the valuables, which are the first thing thieves look for, but also prescription drugs and medications, things like that," said DeBord. "So if you want to have an open house, talk to your agent about how many people you're comfortable coming through, what areas of the house you're allowing them to go into, do we need to lock some areas, do we need to have a second person available just to watch out for folks in the home."

DeBord said a lot of real estate agents opt to have a second agent or assistant with them during open houses, for safety reasons. Doing so is not a requirement, but homeowners can request for two agents to be present during an open house.

"A lot of agents are also notifying neighbors when they're having an open house and saying keep an eye out, if you see anything strange," he said.

Recent open house thefts are one of the reasons DeBord's brokerage firm is hosting a free real estate safety course on October 26. The course will focus on how real estate agents can protect themselves, their clients, and their client's property. To register for the class, click here.

If you recognize any of the suspects seen in the surveillance video in Arlington or Covington, detectives in those communities want to hear from you.