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
that s when things happened, said sam. very bad things. and it was just screaming and yelling in there. until it stopped and i thought that he killed her. sam said he hid in his room the door closed. so i looked under the door and watched him carry her out, he had her over his shoulder. her whole head was covered in red. it was also bloodied. reporter: but sam didn t report his roommate to the police. the next day i asked did you had fun with somebody last night and he beat the [bleep] out of me, and he said that he killed her and i m next if i say anything. reporter: quietly in her almost gentle way detective seymour pushed back. some of the stuff isn t