this was precisely what hans bosma thought, too. but he wanted robertson's independent analysis. >> well, normally, i don't have any information. so i wasn't aware of anything about the vehicle. >> next, robertson flew to modesto, california, to conduct an experiment in doug mouser's car. he wanted to try to recreate the same skin pattern that was on genna's thigh. he placed a live model, the same height and weight as genna in the back of the vehicle over the rear seat belt buckle. it was a hatch back and one of the back seats was broken and was kept flat. the model remained in the same position for 15 minutes, the time it would have taken to drive from genna's house to the dump site. when the model was photographed, robertson and bosma discovered what caused the other mark on genna's leg. >> when he placed her in there, the -- there's carpet on the back of the seat because it lays flat. so he had a nice carpeted area. the carpet bead folds over as he pulls or pushes her over that particular area. and that carpet bead was what one o