and that wasn't the situation with susan schumake. >> lieutenant paul echols was susan's classmate inlege and had kept a picture from her case file on his desk. >> now, you could just look at that picture, you could see that this was a happy moment, a father standing with his daughter, very proud. and knowing the story that i knew by that time that she had been murdered, it was something that always held my attention. >> by the year 2000, almost two decades after susan's murder, a new dna process called pcr made it possible to test a small biological sample where in the past, much larger samples were needed. >> essentially that process is just xeroxing dna. so we're just copying the specific portions of dna that we're interested in analyzing. >> so analysts tested the small biological sample taken from susan schumake's autopsy and were able to identify the dna profile of the killer. >> john paul phillips' dna sample was not on file. so investigators took the extraordinary step of requesting that the state exhume his body. a dna sample was obtained from phillips' bone marrow. it did no