WATCH: Thief uses mysterious electronic device to easily open locked car

SEATTLE -- A West Seattle man is sharing a surveillance video that shows the frightening way thieves are using technology to break into cars.

Watch the video as a man approaches Tom Dahl's truck in this driveway. He tries the handle, but the door is locked. So he takes off his backpack, moves it close to the window. Seconds later, he’s able to get inside.

“He opens the door up,” says Dahl. “The lights went on, it was disarmed.”

Dahl is glad the thief didn’t take his truck. All he did was rummage through the contents of his glove compartment.

“I was smart enough not to carry anything of value in there. That’s what he was looking for.”

But Dahl is concerned about how the thief got in so easily.

“You used to have a wire that you slid down the window, when it was mechanical. But now it’s electronic.”

Cases like this are becoming more common across the region.

Lars Carlson says the man who broke into his car in January also appeared to be carrying something in a backpack.

"It’s running through codes automatically or it's a button they're pushing or something is happening. But whatever it does, it seems to trick the car into thinking he's got the legitimate keys.”

Seattle police say they don’t know exactly what kind of device thieves are using, or how it works. But they are concerned.

“As technology adapts, criminals adapt,” says police Capt. Eric Sano. “We have to be one step ahead of the criminals and to figure it out.”

Dahl says automakers need to do something to give people a little more security. But until that happens, he’s going to share this video with as many neighbors as he can.

“I hope other people pay attention, make sure things are secure and locked, and don’t keep things in your car that are of any value.”