Transcript for New Twist in Adnan Syed 'Serial' Murder Trial

A new twist in the murder case made famous by the popular podcast "Kooerl." Less than two months after being granted a new trial, two new witnesses came forward raising questions about his alibi. Ryth is here with the latest. Reporter: The tight to set him free, two of her classmates from nearly a decade ago accuse someone of lying. It's the case linked to "Serial." The story of Adnans is Syed. Accused of killing his girlfriend. Thousands rallying to his defense. A Baltimore judge ordering a new trial in June. The conviction is erased. Reporter: But this morning, Syed's star alibi witness's story cast this doubt. I was bored to tears in the library. Reporter: Someohe said she was this the library with him when lee was being killed. But this morning, according to documents filed by prosecutors this week, Mcclain's account is being called a flat-out lie. Two of her former classmates say in high school conversation, Mcclain told them she believe sod much in Adnan's innocence, she would make up a lie to prove he couldn't have done it. Those classmates engaging in a testy exchange with Mcclain on Facebook. Saying you know darn well you never saw him that lie Brea. To continue with this story 17 years late sir disgusting. Mcclain replying, wow, this is crazy. I'm not lying about any of this. The now 34-year-old is yed spending almost half his life in jail. I had no reason to kill her. Reporter: His new trial fwranted on didn't grounds. But the judge questioning why Syed's defense lawyer in 1999 lever contacted Mcclain. Major plot point in "Serial." In there was some technicality that would prove his innocence, great. I think, Asia, you might be that technicality. Reporter: Mcclain's lawyer saying the classmates' allegations are bizarre and wholly foughtually untrue. She took to Twitter. They say I'm a liar. I say I'm not. She thinks the state wants to discredit her because she presents a problem to their case. Syed remains in prison while prosecute rers appealing the ruling. Let's talk to Dan Abrams, Nancy grace about that. Let's pick up on the last point. The decision to grant a new trial is not based on the witnesses. Is the new trial definitely going forward? No. When you have a legal ruling like this, prosecutors can appeal. They're appealing the decision for a new trial. Sure, as a technical legal matter, it doesn't really matter because the ruling from the court below relied on something else. Cell phone tower data. But, the fact that there are now question about the star alibi witness has inevitably got to seep into the appeal. If there is a new trial this is Syed's star witness. If this goes to trial, pretty devastating, isn't it? Jt it is. I want to remind everybody that while the cell phone records are what the judge grants the motion for a new trial on, the defense is appealing the decision saying it should have been granted because of the alibi witness, Asia Mcclain, who has tried to make money off this case and her book that is for sale on Amazon, "Confessions of a serial alibi." She's gone on TV, podcasts, taken to Twitter, selling a book. That's not going to help anything. But back to the facts, the cell phone tower issue is the main issue. These two sisters, did you look what they said? Their statement is so rich in detail, and has been corroborated, that they were there at woodlawn high school in a co--op class, with Asia Mcclain, the alibi witness and had this argument. To it's basically two against one. Is this a popularity contest? No. But will it destroy her alibi? Yes. One question is the legal match nations as we work our way through the appeal. The other is let's assume he gets a new trial. She's suppose D to be his star witness. This is devastating. I can't wait for them to bring that book out at trial. I don't thing she'll face being prosecuted for anything like perjury or that. When it comes to the trial itself, the public has been watching "Serial" there's a whole group of people think he's innocent. He's finally going to get his day now. Finally the world is going to see that he's not guilty. Even if he gets this new trial, this information is going to be a real problem for him at trial. Dan Abrams. Dan, I know you're going to disagree, but I want to remind everybody that in the car, the victim's car, who nobody is mentioning, her name is hae lee. She's dead. She was a little high school girl. In her car was the map book with Adnan's print on it. The page of the map where her body was found was torn out of that map book. His fingerprints on the map. They had just broken up. He wouldn't let her go. She had a new boyfriend. She wrote him a letter, let me go. On that letter, he writes, I will kill. Who else killed her? The only person I think realistically that could have killed her would be the other person in the story, which is jay. The one who is talked about so much. Because he's the one who brings them to the car. You have to believe it was either jay or Adnan. You don't disagree with her that much? No, no. He didn't have a dog in the fight. No motive. Plus, he goes to police. That's what I'm putting out there. I don't -- I don't -- We're going to end in a good

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