holdouts first. now back to dateline. >> welcome back to "dateline. " i'm natalie morales. it had been five years since trent digiuro's murder. the case was ice cold, but detectives had just been tipped off by a woman who said her ex-boyfriend, shane ragland, had killed trent as payback for having him blackballed from a fraternity. but the woman was insisting she remain anonymous. so to prove their case investigators would need to earn her trust. once again, keith morrison with "the motive. " >> detective evans knew he had to meet this mystery woman, a woman who was claiming she knew what happened to trent digiuro but was too frightened to talk about it. then finally with attorney tom bullock playing gatekeeper, they made a deal to at least meet face to face, but any more than that? maybe not.