douglas county, colorado, where helene pruszynski was murdered , it's all fit. >> he was how old at that>> 21 when he was paroled here. >> same age as helene. >> yeah. >> it was time to tell lieutenant tony, then boss of the cold case. >> she was like, i know who did it, i know who the killer is for helene. i am like, no you don't. >> he knew all about the investigative dead ends in the case. he had seen plenty of them over the years. >> i'm like, how do you know you do? and she understood the dna, the genealogy, i didn't. she had to explain it. then, there is still that little bit of doubt, do i go upstairs, don't i? so, i did. >> they made the walk upstairs to face the sheriff. >> and they said, we believe we've got him to me this is the guy. >> you've been on the business end of a few other this is the guy conversations where it did not pan out? >> i was. >> detective jensen laid out her case, two brothers, only one in colorado at the time of the murder. and there was another thing, as jensen dug through white's's criminal history, she discovered an old mug shot from 1998. remember th