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GRAPEVINE (CBSDFW.COM) – If you live in the northern part of Grapevine, do not be surprised if you see more police officers in the area.

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Police have upped patrols following a string of car break-ins over a 12-hour span. However, officers said that they need residents to do their part as well and lock their car doors.

Chris Stillwell said that he had a rude awakening when he left to go to work on Wednesday morning. His console was open and his belongings had been rummaged around inside of his vehicle. “I knew something was up,” said Chris Stillwell, “and so I checked our surveillance cameras and, sure enough, someone had broke in.”

Chris Stillwell said that he had left his car door unlocked and the surveillance video showed a person with a flashlight trying to get into their other vehicle before opening his car door.

Shannon Stillwell said that they learned that several of their neighbors had also been hit when they checked their NextDoor app. “They were reporting anything from money to backpacks, guns and tools,” said Shannon Stillwell.

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The Grapevine Police Department said that a dozen cars were broken into in the northern part of the city, and most of them were unlocked. The thieves got away with cash, electronics, purses and guns.

“It’s really concerning, because this has been going on for a few months and it just seems to be getting worse,” said Shannon Stillwell.

“We all think that we live in a safe neighborhood where nothing goes on,” Chris Stillwell added, “but what goes on while you are asleep, you don’t know.”

Police said that they do not know if the crimes are connected, but will have extra patrols in the northern part of the city. They urge residents to remove valuables from their vehicles and lock their car doors.

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Also, anyone with a home surveillance system is encouraged to register it with the Grapevine Police Department. This will let them know to contact you if an incident takes place that might have been captured on video.