how do you feel max shacknai?and performing, for his mother and her camera. >> mom. this is my song, right? >> it is. >> during one of those summers in coronado, a mansion on ocean boulevard was on the market. >> i said let's go by and look. >> they bought it in 2007. but soon there was trouble in paradise, and a bitter divorce in 2009 when max was four. they shared custody and worked to be civil, and it wasn't long before jonah met someone new. >> max told me about it and i said, maybe i should meet her and he said, that would be great, mommy. >> rebecca zahau was 32 and born in myanmar. she'd moved in the u. s. in her twenties. you were okay with her spending time with max? >> max said he had feelings for her, he liked her. at that time i had no concerns because i trusted that jonah, based on our history, max would be safe there. >> and safe in coronado, where nothing bad is supposed to happen. >> tell the operator what is going on. >> hello -- >> july 11th, 2011, max was staying with his dad and rebecca. dina w

dina shacknai would like to see authorities reinvestigate her son's case. do you think they will reinvestigate max's death? >> i think it's the right thing to do. do i think it will happen? i really don't know. >> how does a mother ever truly accept the tragic loss of her child? the ripples keep on spreading to this day. in a place where nothing bad was supposed to happen. >> that's all for this edition of dateline, i'm natalie morales. thank you for watching. another friend is missing. this guy's potentially -- we are confident he was our guy. >> two mysteries to solve. but one recent witness. >> rachel details i need to sedate. before >> i told the truth to the best of my capability. >> police wondered had another murder been planned? >> they said if you would have gone back that day, they wanted to kill you. >> did rachel have a secret -- >> what did you do? >> i think you know what i did. >> -- would she keep it? >> this is as diabolical as any case i've ever seen. >> or was the curtain about to close? >> rachel is kind of the last piece? >> correct. >>

detective shacknai heard about the men that police talked to a few days before lydia's attack.as acting up, in the fort collins bonner district. wasn't that the man that denver police had under surveillance? >> this could, possibly, be related. he's in fort collins, and their work with it. >> what did you think when you heard that? >> i said, thank goodness, and that maybe we could look into. >> long shot, they figured. detective shackled called the checked of guerrilla in denver. >> i laid out what happened, and what happened. >> they said he's at the place of, various bleach on, her and around the house, and he was silent on the other end of the phone. then, finally, he said, oh my god. >> she said, what do you think? i said, i think it's him. >> i get chills now, talking about it. it was quite the moment. >> who was travis? a serial offender, hunting women? was he having another, even now? the two detectives were convinced of it. but, as badly as they wanted to lock him away, they just did not have sufficient evidence. so, travis was a free man, roaming fort collins, at will