in, they said they heard screams coming from the park. she was found naked and bound with red duck taped. when you see the photos, you can feel the terror. he left her for dead. we were shocked. as a dna laboratory that there were no other offenders. how is this guy not in the system? then, one day, you ve got a call. they said there s been an update on the case. it was like finally. i ve been thinking about who this guy was for so long, i don t think anything could have prepared me for that answer. how do you wrap around mind around the fight that someone you trusted this. i can picture him smirking. a second customization? yes. might screw up. what kind of person does that kind of thing? exceptionally sick, evil. reporter: the evening arrows warm and thick with anticipation. college students, returning a new, mix and drank with young locals. darkness fell on colorado. one more night to take a lusty bite of the flooding summer. that last friday
the sample from her only person of interest, amber s friend, aric vanagunas. we thought of possibly could ve been eric, the person she was with the night before. reporter: who can know what a person is capable of? even a young man who lived with his parents and helped out church. and then, nearly a week after the attack on amber, dna analyst melissa grass picked up the phone and call detective seymour with the news. for the first part of the conversation was exciting, we were able to develop a dna profile. reporter: a full incomplete genetic picture of the suspect, which they could use to i.d. amber s attacker. that was the good news. the only good news. we were pretty shocked as a dna laboratory, we were surprised that there were no other cases, no offenders that were matched to. reporter: no match. none. zero. not one single hit among the