What's the Problem With Eyewitness Testimony?

A patrol officer on cabin creek road finds damien's black suv. He looks in the window and he sees that the driver's seat is reclined. Some unusual things about him, his shoes are untied and his pants are unzipped. They don't really see any footprints around the vehicle, or tire tracks. But it doesn't take them long to find the body, because it's only a hundred yards up the trail. It was actually bought gasoline by noose that has been fashioned from red jumper cables.