Transcript for Police grow suspicious of missing nursing student Holly Bobo's brother
Reporter: And now we have the latest on the desperate hunt for Tennessee nursing student holly Bobo. She was taken from her home by a man wearing camouflage. This morning, there are some new clues. Did she know her alleged abductor? Reporter: Clint Bobo was the last person to see his sister holly alive, as she was led into the woods by a man. I knew that he was wearing camouflage and he had what appeared to be a black object in his hand. You also described his height, and weight, and hair color. Yeah. I estimated him to be about 5'10" and about 200 pounds. What color hair? I really don't remember focusing on his hair. But you described it to police as being dark. Yeah. Reporter: The pressure is enormous, people are puzzled by Clint Bobo's account of the abduction. At the time, Tennessee bureau of investigation's Terry Dicus is heading up the case. There were a lot of people that felt very strongly Clint was lying, and that Clint telling the truth would be the secret to solvin' this case. Did they tell you they thought your story was strange? It was just question, after question, after question. Now, of course, they did check me. They said for scratches and so I took my shirt off. That was that morning that she disappeared? Yeah. Yeah, that was that morning. Suspicion was that quickly turned toward you? You were there. I was there, yeah. I was there and holly was not there. Reporter: Police search Clint's computer, monitor his phone calls, and polygraph him, twice. Have you told everything you know about that morning -- Yes. That your sister disappeared? Yes. I have told everything. What has it been like to lose one child and have the other child be the focus of so much suspicion? I felt like we had lost one child and have, was having to -- to fight for the other one. But I knew the truth would always come out in the end. Reporter: Eventually, Clint is cleared and investigators turn their attention to another man from the county. Terry britt was a registered sex offender who lived fairly close to the Bobo home. He lived, also, very, very close to where some of her property was found. The first time I interviewed him, I was like, "Oh my god. This guy did it. This guy did it." You thought that the first time you interviewed him? Yeah. I thought that before I interviewed him, actually. According to Terry Dicus, Terry britt did have, for lack of a better term, a type. He liked pretty blonde, blue eyed girls. Uh, and holly fit that type. Reporter: The dark underbelly of Decatur county, the criminal underworld of drug addicts and sex offenders is a foreign country to Karen Bobo. We didn't live in that culture. We lived in our own little circle -- So you weren't even aware of it? That that world existed? Absolutely not. We were just hardworking family. I thought that's how everybody lived. Tell me about Terry britt. He is a -- horrible, horrible human being. He spent the majority of his life in prison for kidnappin' and rape. And he absolutely perfectly matches the description that Clint Bobo provided of holly's abductor. His entire alibi was a lie, from start to finish -- complete and total fabrication. Reporter: His alibi was that he was buying a bathtub with his wife at this salvage yard. Problem is Dicus says the store has no record of that sale. Dicus does not believe it's a coincidence that britt's home is in northern Decatur county, in the general direction holly's cell phone was moving the day she was taken. You executed a search warrant on Terry britt's house. And that involved bringing cadaver dogs. Did they find anything? The cadaver dogs alerted to two of britt's vehicles and several tools around his house. Somebody has been decomposing in or around these vehicles, in or around these tools. So you seized the vehicles and the tools and tested them for any D.N.A.? Correct. No D.N.A. Correct. Reporter: Undeterred, police wiretap britt's phone and put a bug in his house and listen to his conversations. The wiretap did not result in anything. We didn't have any type of admission on that. And I think a lot of people looked at that as exoneration. Reporter: But not Dicus. And he says largely because of this -- a recording of a chilling conversation he had with britt. Britt seems to actually fantasize about what holly's kidnapper might have been thinking. She's young, pretty, perfect, somewhat, body. Okay, like a toy. He can't wait to get her to where he's going to take her to, because he's wanting that body. But here comes reality, now I've got a body, what am I gonna do with it? If you keep it, you gotta feed it, you gotta hide it, and if you kill it, what are you gonna do with it? The hairs must have stood up on the back of your neck. The way I took it is he's relivin' the story. And when he gets to the point where she's no longer alive, he changes from talkin' about her as a person, talk about her as an it. Reporter: But britt continues to deny he was involved, and investigators cannot seem to find compelling evidence to prove otherwise. Many in the tbi feel it's time to turn to other suspects. Not Dicus, though, he just can't let go. Were you asked to leave the investigation? I was taken off the investigation, yes. Because you felt passionately that they had -- a suspect that you should be pursuing. Yeah. And nobody else agreed? Well, not -- I wouldn't -- no -- not -- nobody else agreed, but the right people didn't agree, is more accurate. Reporter: Dicus was reassigned, and then leaves the tbi altogether. The agency says Dicus was benched because he developed tunnel vision and had lost his ability to be objective about the facts of the case. The investigation meanwhile, seems to go nowhere. Holly's family is increasingly frustrated. Until your child is found or you know what happened to them, I don't think anyone could ever do enough in a parent's eyes. Reporter: But in the depths of the Bobo's despair, suddenly a stunning turn We have a major break report, a suspect is in custody this morning. Reporter: Police say they've found their man -- make that men. And then they find something in the woods. I once again got that same, "It's her" feeling.
This transcript has been automatically generated and may not be 100% accurate.