GREEN BAY, Wis. (WBAY) - You might want to think twice about letting your car warm up while you're not in it.
Green Bay Police have received 35 reports of stolen cars, including this one, this year. Some have been recovered in other cities.
Green Bay Police are seeing a sudden and big increase in stolen cars across the city.
Investigators say they've seen nearly twice as many stolen cars this year as last year.
"That's a lot for Green Bay. That's a lot. it's raising some alarms for us," says Green Bay Police Commander Jim Runge.
It's happening in all kinds of neighborhoods, on the east side and the west.
"Whatever you have, there's somebody out there that wants to take it from you, so do whatever you can to protect it," says Runge.
And really, he says, it's easily preventable.
Step one: Don't leave your keys in your car.
Step two: Lock your doors.
Police say doing those two things would likely have prevented a vast majority of cars from being stolen.
A year ago at this time, they'd seen 18 stolen cars.
Since January 1 this year, they've had 35.
There were seven last week alone.
The thieves don't even have to hotwire them.
Commander Runge showed us a map pinpointing each stolen vehicle across the city. Twenty of them show people left their cars running or at least left the keys inside the vehicle.
"We, as citizens, are making it too easy for some of these criminals," says Runge. "All they do is go around and start pulling doors, and if they have an open one, they go in and look for the keys."
Police think two unrelated groups of teenagers are behind the crime spree.
They've even arrested them, but detectives say the teens don't stay locked up for long.
"It's hard to keep 15, 16 (year old) kids incarcerated, so they have not felt the consequence yet of their behavior, so they go right back out and re-offend," says Runge.
He says the teens take the cars for joyrides, then ditch them when they run out of gas.
They've recovered them in Superior, Oshkosh and several other places.
"The Oshkosh one, they (Oshkosh PD) had a stolen car. Whoever was working our case said, I bet you they'll find one of our cars down there, and sure in heck they did, and their car turned up in Milwaukee," says Runge.
Police say many of the thefts happen at night or early morning, but they are finding them at all different times and places.
And it's not just in Northeast Wisconsin.
"If it's happening in Green Bay, our criminals didn't invent it, so it's happening in other places," he adds.