investigators believe richard van dusen was pulled from his jeep and shot outside the vehicle. his wife karla was sitting in the passenger seat and was shot through the windshield. but on the steering wheel, investigators found blood which did not come from karla or richard. >> the samples that were tested from the steering wheel were consistent with being human blood. those samples were tested to develop a dna profile. >> perhaps the killer nicked his hand while cutting the seat belt to remove karla's body, and the blood dripped on to the steering wheel while he drove the jeep to the dump site. investigators asked their initial suspect henry sullivan for a dna sample. testing showed it was not his blood in the car. >> sullivan wasn't involved in the crime. so the mystery was how did his car get there?