By Tom Mustin

CENTENNIAL, Colo. (CBS4)– It’s a high-tech device that law enforcement says is leaving car owners vulnerable. Homeowners in Arapahoe County contacted CBS4 to send out a warning to others.

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The Arapahoe County Sheriff’s Office says since June, thieves have broken into 306 cars in the Centennial area. More than half of the vehicles have shown no sign of forced entry.

(credit: CBS)

People say they have evidence crooks are using new technology to gain entrance to their cars.

“Seemed like they just went from house to house,” says Centennial resident Donald Meyer.

CBS4’s Tom Mustin interviews Centennial resident Donald Meyer (credit: CBS)

He believes high-tech criminals have targeted his Centennial neighborhood.

“I work in the electronics industry, so I knew they had something that clones the unlocking capability of the vehicle,” Meyer told CBS4’s Tom Mustin.

(credit: CBS)

Last week Meyer’s home surveillance cameras caught what appears to be two young men somehow electronically opening the door of his neighbor’s Ford f250.

“You could see as they approached it they used some kind of device in their pocket to unlock the doors. Rummaged through it for a couple of minutes then took off up the way, presumably to do some more to the same neighbors,” he said.

(credit: CBS)

At least four vehicles were hit the same night on the same street.

The crooks may be using scary new technology, specifically two pieces of electronic equipment that are being used by car thieves nationwide.

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First, the relay attack unit, which is like a small laptop, intercepts the key fob signal from as far as 25 feet away.

(credit: CBS)

The unit then relays the signal to another device the size of a cell phone. That device can open the car door with a wireless signal.

“As they develop their technology, thieves develop their technology,” said Mike Greenwell with the Metro Auto Theft Task Force.

(credit: CBS)

He says as auto technology has improved, criminals have evolved as well.

“It’s no different than your cell phone or computer,” said Greenwell . “We try to think of new ways to protect it; they come up with new ways to get into it.”

Greenwell says car owners need to be vigilant. And he has a message for the tech savvy crooks.

(credit: CBS)

“There’s a lot of smart people I’ve put in jail. If they would just use their intelligence for good, this world would be a lot better place.”

The electronic units were originally created in Europe for car manufacturers and law enforcement to test a vehicle’s vulnerability. They eventually ended up on the black market.

The Arapahoe County Sheriff’s Office says they have no way of knowing how many of the cars were broken into using the new technology and many may have simply been left open. Their advice: lock your car door, and remove all valuable items from the vehicle.

Also, close your garage door and report any suspicious activity.

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Tom Mustin is CBS4’s Weekend Anchor. He has been with CBS4 since 2002, and is always looking for great story ideas. Connect with Tom on Facebook or follow him on Twitter @TomCBS4.