Bicycle detail

My son and his friend were playing on the trail by the Jared Jensen park at the creek and left their bikes on the ground. They explored for approx. 10 minutes and came back to find their helmets and coats, but both bikes missing. My husband and I drove around the area but saw nothing. The kids asked people in the area and at Jared Jensen park and two kids said they saw the bikes being ridden past the park into the Sunny Alps street neighborhood. His is a GT Aggressor, gray with blue accents and added kickstand. Large mens mountain bike. I have not seen hers but she said it looks similar but smaller with a black water bottle holder and a silver bell. Police report has been filed and I'll update with the case number as soon as I have one.