the lab and -- >> within four hours, we had a positive hit on mr. jones. >> we at "dateline," cover a lot of murders. less than 84 hours after this homicide rampage began, investigators were confident they had ided their killer. >> we knew he was our suspect and murder. >> at the same time, the dna was being analyzed, detectives were retracing dwight's steps. sometime before he was place under surveillance, dwight had contacted the residence of this home in fountain hills. a maricopa county sheriff deputy. >> they immediately recognized there was a gentleman inside that appeared to have been shot. they forced entry and upon doing so, found another victim, a woman, who had also been shot