Making a Murderer star Steven Avery, who was convicted of murdering a woman in 2007, has a new attorney and she is vowing to set him free, claiming that he was framed. Kathleen Zellner, a famed defence attorney, even claims she and her team have identified "a couple" of suspects she believes may have actually killed photographer Teresa Halbach.

Zellner recently spoke to Newsweek about her team's strategy to get Avery released and exonerated for the murder. "When I watched the Avery case, I felt that the attitude toward him by the prosecutors and the state was that he was disposable. It was almost like a class thing. [His family] didn't matter, they had no power," Zellner said. "The longer I watched it, the more angry I got."

But who is Kathleen Zellner?

According to Newsweek, Zellner has secured the exoneration of 17 prisoners and has won nearly $90m from wrongful conviction and medical malpractice lawsuits. The tough-as-nails defence attorney once dropped a headless lamb into a creek while investigating the rape and murder of a child. The Oklahoma native has also managed to coax 21 confessions from a serial killer, Newsweek noted.

Zellner has been the president of her own law firm, Kathleen T Zellner & Associates PC, since January 1990 and is a member of The Innocence Project, according to her LinkedIn profile. Her motivation to help Avery stems from her desire to help innocent people. "What drives me is the abuse of power—the bullying and the victim. I have such a strong reaction when I see people who can't defend themselves," she said.

In the Avery case, Zellner said her team has identified a number of other possible suspects. "We have a couple," she said. "I'd say there's one, leading the pack by a lot. But I don't want to scare him off. I don't want him to run." Avery and his low-IQ nephew Brendan Dassey—who confessed to helping his uncle rape and murder Halbach—were framed for the young photographer's murder, Zellner said.

The defence attorney told Newsweek that law enforcement and defence attorneys in the initial case failed to investigate the victim's life. Zellner said that Halbach was a nice person who was just beginning her career but suggested she had "bad judgement" when it came to men.

In order to free Avery, Zellner will need to find new evidence to reopen the case as he is all out of appeals. "We have to have new evidence that could not have been obtained before that would result in no juror believing that Steven Avery committed the crime," she said. "So that's the standard — it's kind of a high hurdle to jump, but we can jump it with the new technology. With someone who's innocent, you can definitely jump that hurdle."

According to Newsweek, Zellner is now speaking with experts and organising new forensic texts. She claims to have identified leads local investigators failed to pursue, including phone calls Halbach made two days before her murder to a man recently arrested for sex crimes. Zellner also plans to go out against Avery's previous defence lawyers Dean Strang and Jerry Butling.

The case will hardly be an easy one for Zellner to take on, especially in light of Netflix's show on the case and the evidence stacked against Avery. Zellner, however, remains undeterred.