Transcript for New Lawyer Talks Evidence in 'Making a Murderer' Case

First, the new developments in the case that has transfix sod many Americans including the people sitting at this desk. We're talking about Steven Avery, the character at the center of the netflix doc series "Making a mur rer." His new attorney says she's optimistic touting new evidence that's never Beene tested. Reporter: It's a murder mystery that has much of entire country wondering who really did it. Now a new attorney has taken Steven aif I have's case and things aif I have should be a free man. I want people to know that I didn't do it. I'm innocent. Reporter: Reaching out from jail, his new attorney tweeting this hand-written know. I want every forensics test possible done because I am innocent. Zellner, a high-power attorney known for overturning wrong convictions wasted no time in criticizing the former prosecute person taking to Twitter. Defending her client. We'll do everything necessary that's forensically available. Reporter: Cleared in 2003 for a rape he didn't commit, only to be charged again two years later for the murder of 25-year-old Teresa Halbach. It's hard enough to go to prison for something you didn't do. But then you have to do it all over again? Reporter: Zellnes noticed seven of her tweets mysteriously dele deleted. She says she didn't delete them. She doesn't believe Twitter did either. Tweeting, so if the truth hurts, just delete it. Focusing on the DNA evidence found on Halbach's Rav 4. The attorney purchasing the same car model. I want to examine what was not tested that should have been. Since 2007, there have been significant advances in frezic testing. Clearly, there are other people we're looking at. That's always done in a case like this. Reporter: And Zellner is hopeful they'll get movement in the appeals process in the next 30 days. This case keeping everyone on the edge of their seats. Thank you. Great to have you in studio. And it's great to have ind

This transcript has been automatically generated and may not be 100% accurate.