Transcript for Woman Befriends Key Witness in Chandra Levy Murder Trial: Part 4
Reporter: It's been nearly a decade since Chandra levy's disappearance, and now prosecutors finally bring murder charges against ingmar Guandique and take him to trial. A case that once riveted the nation. Reporter: What was it like for you, being at that trial? It wasn't easy. Reporter: Cameras aren't allowed in the courtroom but the emotional testimony from the two female joggers who survived Guandique's attacks take the gallery's breath away. It's almost like Chandra is testifying through these women on the witness stand. Reporter: Gary Condit has been diligently avoiding the spotlight. But now finds himself right back in the middle of it. Mr. Condit, anything you want to say? Reporter: Called to testify, he heads to court with a media circus in tow. I think he was kind of the elephant in the room and they needed to demystify him. Reporter: Former U.S. Attorney Tim Heaphy prosecuted cases in the D.C. Office. It would be too easy if he were a silent presence for the defense to suggest directly or subtly that he was the real culprit. Reporter: A Condit sighting always makes headlines, but now prosecutors are hanging their case on a secret weapon. One of the prosecution's star witnesses. Reporter: Meet Armando morales, a California gangster with the record and the tattoo to prove it. That paw print marks him as a member of the Fresno bulldogs, a gang notorious enough to merit a documentary on the history channel. Here's morales' cameo. A bulldog named Armando "Mousey" morales. Reporter: Back in 2006, morales and Guandique were sharing a federal prison cell for separate crimes. Now on the stand, morales makes a stunning allegation -- Guandique made a detailed confession to the levy murder. His testimony was convincing. He knew certain things. Reporter: After morales' testimony, Guandique is found guilty and sentenced to 60 years in prison. The result of this verdict may be guilty, but I have a life sentence of a lost limb missing from our family tree. Reporter: One of the country's longest ongoing murder mysteries is finally over. Or is it? The conviction starts to wobble two years later when the defense discovers that the snitch morales concealed a crucial fact from the jury. He had a history of working with law enforcement. Knowing those prosecutors, my guess is they had no idea until after the fact about Mr. Morales' prior cooperation, maybe they should have. Reporter: Honest mistake or not, it's a big enough deal to make some very big news. The accused killer is getting a new trial. Reporter: What happened for you when you heard that Guandique was going to get a new trial? There was a part of me that says, well, maybe Mr. Condit's going to be asked to come back and talk a little bit more in-depth. Reporter: Susan's instincts are spot on. A major development in one of the biggest murder cases of the last two decades. The defense is pointing the finger at California congressman. Reporter: Guandique's attorneys allude to a defense straight from "Fifty shades of grey." They wanted to develop information about other relationships he had that may have involved rough sex play. Reporter: It looks like Condit's sex life could be on trial. But wait. Okay. Reporter: Out of nowhere, this woman is about to crash into the case. Things will never be the same. A 15-year-old murder case is turned on its head because of you. Did you ever expect that? No, absolutely not. Reporter: She's reluctant to talk to us. She says she's in danger, and keeps her whereabouts secret. You don't want us to say where you are. I feel unsafe. Reporter: Her name, babs proller, a small-time actress originally from Germany. An extra, coincidentally, in the smash political drama, "House of cards." We overcame those tensions. Reporter: So how exactly did she land a role in a famous D.C. Murder case? I mean, sometimes real life, I think, can be -- Reporter: Stranger than fiction. Stranger than fiction, absolutely. Reporter: Her strange tale begins this past July in annapolis, Maryland. Babs is going through rough times and is staying for a while at this country inn and suites. During her stay, she crosses paths with a mysterious middle-aged man who calls himself "Phoenix." He was very kind. He was very friendly. He seemed like a very personal, nice guy. Reporter: Was there a spark going on here? No, no. There was no spark. Reporter: But they grow do closer and a friendship ensues. Phoenix even babysits babs' golden retriever buddy while she is out of town. That's him with buddy and buddy actually has a paw up there on him. Reporter: But don't let those sweet selfies fool you. Phoenix has a paw of his own. That tattoo, marking him as a former gangster from the Fresno bulldogs. He is in fact the same snitch who testified so convincingly at the Chandra levy trial, Armando morales. His face changed completely. It went from this gentle, kind, caring guy, into a look that almost scared me a little. Reporter: Trusting his new friend, morales reveals he's just done 20 years in prison. I said, "20 years? You must've almost killed someone to be in for 20 years." And his answer was, "I wish it would've only been one person." Reporter: So what's he doing here? Morales explains he's the key witness in the upcoming retrial of ingmar Guandique. While preparing to testify, the government has put him up in the hotel with a cell phone, a room key, and some cash, and strict orders not to blow his cover. What did you think? I was intrigued of his involvement, what he knew. Reporter: She's intrigued enough to continue the odd friendship, but also scared that the criminal could hurt her or those close to her. So she makes a fateful decision. Babs says that, for her own protection, she begins recording her conversations with morales in the hotel, in the car, even in this storage locker where he's helping her organize her things. This is where you recorded it all, mostly. I did. Reporter: Next, the secret recording that will rock the levy case, and get a convicted killer out of prison. He told me he didn't know he killed her. What started as a circus ended as a circus.
This transcript has been automatically generated and may not be 100% accurate.