A home security camera system caught burglars rummaging through a family's car and garage while the family was sleeping inside.

The Trenton, Ohio, wife and husband had recently installed the home security system, and were shocked to see the burglars pawing through their belongings and scouring through the contents of the garage. The thieves also walked away with the family's garage door opener, reported WKRC Local 12 in Cincinnati.

"It's a horrible feeling, you know," homeowner Cody Agee told the TV station. "Nobody should have to go through that." About 16 families were affected by the burglaries, police said. The thieves took off with cell phones, GPS devices and even a hand gun.

Each year, about $1.23 billion of personal items are stolen from people's cars, authorities say. You don't have to install a home security system to avoid these thefts, though. The first step to protecting your valuables is park your car in your garage, if you have one. If not, always make sure you take valuables with you and lock your car door, even if you think your neighborhood is safe.

Amazingly, a large number of thefts come from owner behavior: Some 40% to 50% of thefts were the result of driver error, like leaving keys in the ignition or leaving the doors unlocked.

Keeping your car clean also helps avoid thieves, who might be willing to wade through your empty Burger King bags hoping to find something valuable. Also, hide things that might end up being bait for thieves, like iPhone connector cords or mounts for GPS systems or cellphones.

For more tips on avoiding car break is, check out this: