larry montgomery: yeah.or: after listening to the interviews time and again, the evidence whisper had no doubt sam killed cathy. but could the team prove it beyond a reasonable doubt? detective daron wyatt: ultimately in cold case murders, time becomes one of our friends because technology changes. narrator: at the time of the murder, dna tests could only be done on big samples like blood spatter. but in the years since, analysis became possible for touch dna, the microscopic calling cards many of us leave behind just by putting our hands on something. if sam and xavier did place cathy's body in the car's trunk, maybe, thought larry, there would be touch dna on her clothes. larry montgomery: we had searched for dna in the areas that might be grabbed, especially areas that might be grabbed that don't have blood on them from cathy. josh mankiewicz: so you looked what-- on the ankles and under her arms? larry montgomery: ankles, arms, i think under the legs. josh mankiewicz: daron wyatt sends out the evidence f