SIOUX FALLS, S.D. (KELO) -- Sioux Falls Police are sending out a reminder to drivers after 4 vehicles were stolen Friday morning. One was reported around 6:00 a.m. It wasn't running but the keys were left inside. UPDATE: Yankton victim found beheaded The other 3 were reported from 7:00 a.m. to 10 a.m., all were left running. "It's really easy to spot a running car when it's really cold like this. Some people jump on that opportunity and steal the car so," said Officer Sam Clemens. Police say if you are going to let your car warm up, make sure you are keeping an eye on it.