own crusade. then after more than a decade of searching, a phone call. they got information there was a match. can we get a conviction on just the dna? and there was something else, something about bonnie herself. it was almost like she knew something. keith morrison with justice for bonnie. bonnie was an 18-year-old whose future was filled with promise. she had a boyfriend and just started college. then bonnie was murdered. her body found floating in a creek. investigators quickly discovered a crucial clue. the killer had left behind his dna. but prosecutors need more than forensics to get a conviction. here s keith morris.
her tigger because she was bouncy and fun, and so sweet to everybody. she was involved in sports. she was coaching the kids in swimming. she started students against drunk driving. she was the very first girl to be on the wrestling team at the high school. reporter: bonnie had a serious boyfriend, cameron, who had left that summer to start college at the university of california. she used to record herself singing and talking to him and sent him cassette tapes. she was crazy about him, yes. they were madly in love. reporter: but now suddenly bonnie craig was dead. at least that s what her mother karen had been told, but as she flew home to alaska, she struggled with denial. i believed flying back that if i got there she might even be at the airport saying, mom, i m sorry. it wasn t me. it s all just been a terrible mistake.
we would ride the bus, you know, for a week straight just to talk to all the people on the bus. reporter: for a week? yeah. to see if they saw anything, see if they heard anything. reporter: nobody heard anything. no, no one could remember seeing bonnie that day. reporter: winter came. karen, consumed by grief, rage, guilt about her undercover drug work, was now a single-minded crusader for bonnie. nothing else mattered. nothing at all. it s unbelievable, you know, as the mother, i abandoned my kids and started looking for a killer. reporter: it was months before the troopers gave karen the rest of the news about what happened to bonnie. in the last minutes of her life. coming up as investigators began looking for possible suspects, they looked first close to home. i remember just straight up asking him, dad, did you kill bonnie?
that s also when the medical examiner told her about one extremely important piece of news, horrifying, but potentially useful. bonnie had been raped as well. and as awful as that was, it left one sliver of hope. the killer left behind his dna. match it and they d solve the case. so who was it? it couldn t have been the boyfriend, cameron. he was down in california going to college. reporter: troopers said they looked at karen s work as a undercover police officer and determined that the men in the drug buys were not involved either. but there was one man very close with opportunity who returned home to anchorage from an out of town trip just the night before the murder, bonnie s step-father, karen s ex-husband, samantha s dad. and i remember that being a really unsure, scary feeling. in my mind it didn t make sense. my dad is not and never has been a violent man. so i remember just straight up
. welcome back. teenager bonnie craig s body was found in a creek outside of anchorage and the evidence was saying bonnie had been murdered, just as her mother, karen, knew all along. she insisted state troopers were not doing enough to find her daughter s killer, but detectives were about to uncover a clue that would give the grieving mom something she so desperately needed. hope. here again is keith morrison. it was a standoff, tense and unpleasant. karen, the grieving mother, furious at a team of state troopers she did not trust, determined to find out herself who murdered her bright, beautiful bonnie versus detectives who, in turn, did not trust her. and so told her little about what they knew and what they were learning. but they eventually let her see the autopsy report. that s when karen saw a dozen or so brutal head wound.