FORT WORTH (CBSDFW.COM) – Imagine this… you lock your vehicle and walk away, only to return to find it ransacked. Courtney Cornwell of Fort Worth thought her husband had been looking for something, or that she had accidentally left her car unlocked.  Instead, their home surveillance video revealed a tech savvy thief.

“You can see his hand go up against the handle and set there for a minute, and then my lights flash whenever you unlock with the key fob… he even reset the alarm after he was done,” says Cornwell.

Soon, a neighbor posted a similar video, and a warning. Cornwell quickly noticed that it was the same man that ransacked her car Tuesday night.  “A lot of anger,” says Cornwell, “a lot of anger.”

Thief braking into car. (CBS11)

We reached out to local police departments and auto security companies for answers.

“The code, it sounds like, it’s getting captured and then later on it’s being used and repeated back and being used to unlock the vehicle,” says John Schellsmidt.  Schellsmidt owns Audio Depot in Arlington.  He says thieves are exploiting auto technology in much the same way that criminals have been able to steal information off of credit card magnetic strips, without having the card.  Some are calling the devices used to capture the codes “repeaters.”  He says after-market alarms are less vulnerable.

“When you use one of their remotes, the code changes… so the next time I hit the remote, it’s a different code.”  He also says car owners targeted should contact their dealers regarding a possible fix.

A spokesperson for the Arlington police department confirms that their auto theft officers are aware of the devices, but had not heard of any showing up in North Texas… until now.

Fort Worth neighbors are busy sounding the alarm.

“Very, very, very scary,” says Cornwell.  “Can he do that with your house alarms, too? What’s next?”