Reporter: After months of exhaustive investigation, a positive DNA match and a rigorous interrogation -- So when are you lying? Are you lying then, or are you lying now? Reporter: Ken Brennan finally... See More
Reporter: After months of exhaustive investigation, a positive DNA match and a rigorous interrogation -- So when are you lying? Are you lying then, or are you lying now? Reporter: Ken Brennan finally thinks he knows what happened in Miami in the wee hours of February 21st, 2005, after this fateful meeting between inn budnytska and Michael Jones. He seems to be very casual right here. Very casual, just getting onto the elevator. They engage in some type of conversation. Reporter: There's no video of any conversation because remember, for privacy reasons, there are no cameras in the elevators or the upstairs hallways. But Brennan knows the two spoke because back in the interrogation, Jones knew inn had been injured working on a cruise ship. Talked to her. Start telling me something about she was disabled, she got hurt on Tom cruise ship or something. Reporter: Inna then goes to her room. We know that because, remember, the key card security log records her swiping the key at her door for the last time just moments later. And on top of that, the red jacket inn is wearing was recovered on the floor of her room on the fourth floor. But inn doesn't stay there. I know the victim said that she believed it happened in her room. But the evidence doesn't present it to be that way. What the evidence presents is that she was in her room, but somehow or other, I don't know if she was drugged or, he convinced her to have a drink with him or something. But somehow other they ended up in his room, which is on the next floor up. And they end up in his room, and I believe that's where the sexual assault and kidnapping took place. This was in actuality the crime scene. Reporter: Brennan believes that after beating and raping inn in his room, Jones stuffs her in his suitcase, casually strolls out of the hotel at 5:28 A.M. Without attracting the attention of the night manager, George Perez, and drives off. Now, he's in a hurry, because he's got to be back in time to be at work at the boat show that morning. What I think is, he exits the hotel, he makes a right turn. He goes to the first major intersection, because he's not familiar with the area. He's not from the south Florida area. Makes a right on 122nd avenue. This is an empty cul-de-sac. This is the first opportunity he's seen from the hotel that gives him the opportunity to dispose of the body. Reporter: Jones dumps inna's body, turns around and makes it back at 6:21 A.M., with time to spare. He saunters into the hotel restaurant at 7:59 and joins his friend at breakfast. Then, they head out to the parking lot and off to work. Just like another day at work. Reporter: But after almost a year of sleuthing, Brennan's investigation is about to unravel. Inna refuses to accept his theory, instead sticking to her original story that the attack happened in her room. I didn't go nowhere. I didn't go to nobody's room. I remember myself going into my room. That's what I remember. Reporter: And remember, inn had told police she'd been attacked by two white men with Spanish accents before picking Jones out of that lineup. And even after she'd I.d.'d Jones, she claimed he was just one of two assailants who raped her in a car. She did give contradictory statements. Reporter: Inna's foggy memory could have resulted from the massive head trauma she sustained. Or perhaps Jones slipped her some kind of drug. In any case, she made a flimsy witness. The prosecutor's office was uncomfortable with the fact that inna's memory was in bits and pieces. With jurors, it's hard, really, to predict they would feel, the way it comes out. It may throw some doubt. Reporter: To be clear, except for the circumstantial evidence on the video, the case is becoming thin. There's that DNA match, but it only proves sexual contact. Not necessarily rape. Under interrogation, Jones never confesses to Brennan or Foote. He bombs a polygraph test, but those aren't admissible in court. The famous suitcase is never recovered. And unfortunately, just like Michael Jones' rental car, his hotel room has been cleaned countless times in the year before he was ever identified, probably destroying any evidence. Jones' defense attorney smells the prosecution's weakness a mile away. We believe that they couldn't prove the case beyond a reasonable doubt. The Miami Dade police department, I think, the detectives there believed that since they had DNA, and a suspect to match that he must have been the one who did the rape and the beating. But there's no evidence that he did that at all. Reporter: That's a bit of a stretch. But bottom line, it's enough to make the d.a.'s office give up on a lengthy prison sentence. They didn't feel they could win a case if it went to trial. You don't know how a jury would feel. So, the prosecutor's office decided to offer him a plea, which he took. Reporter: Two years. Two years. Reporter: Two years. I was upset. Oh, you can't let this guy out. I just told them, you can't. I was angry. I was angry. But I couldn't do anything. I'm not familiar with the justice system. But I was upset inside, yes, I was upset. Reporter: In fact, everyone involved in the case is upset everyone, that is, except ken Brennan. That didn't bother me either. I said, hey, listen, don't worry about it. Reporter: The dogged investigator has yet another hunch. This wasn't his first time at the rodeo here. He's done this before. Reporter: And the hotel security cameras are about to give up one final secret about Michael Jones.
This transcript has been automatically generated and may not be 100% accurate.