Transcript for 'Making a Murderer' Prosecutor Says Producers Left Out Key Evidence
face justice there. Robin, George. We move to "Making a murderer" generating buzz and petitions calling for the convicted killers at the center of the story to be pardoned raising questions about whether evidence was planted but the prosecutor in the case is fighting back saying the producers left out key evidence. We'll hear from him in a moment after this report from ABC's linsey Davis. Reporter: The netflix series "Making a murderer" has hundreds of thousands in an uproar after watching the story of Steve Avery. Who was freed after spending 18 years in prison for a crime he didn't commit. Not long after Avery is arrested for the murder of Teresa hallbeck, a young photographer whose charred remains were found on his property. He wanted us to help him get rid of the body. Reporter: The series showcases riveting courtroom testimony questioning the state's evidence against Avery and his then teenage nephew. Because I didn't really do it. Reporter: The defense attorney suggests he was framed. You're hearing the evidence of the conspiracy. Reporter: Avery and his nephew were convicted of her murder and sentenced to life in prison. Nothing in your life suggests that society would ever be safe from your behavior. Reporter: Now outraged viewers want them freed. More than 200,000 people have signed a petition on change.org and another 30,000 are asking for presidential pardon for Avery and his nephew. We wanted to present as many sides as we could but at the same time we also wanted to tell a compelling story. Reporter: But in a statement to ABC news, prosecutor ken Kratz says important evidence was left out of the documentary, evidence like Avery had drawn a torture chamber while in prison, that Avery called the vic's job to specifically request Halbach the day she died and called her cell phone three types twice using the star 67 feature to hide his identity. The filmmakers say they were always concerned with fairness and accuracy. From my perspective it's a fair representation of what we witnessed going on and that the prosecution and the victim's family have voices in this series, we hear them talking about how they're feeling. We hear the prosecutor talking about why he thinks his case is strong. Reporter: When ABC news approached netflix, we were told there was no further comment. For "Good morning America," linsey Davis, ABC news, new York. Thanks, linsey. We are joined by the former prosecutor at the center of that case, ken Kratz. Thanks for joining us. We outlined some of the evidence you believe was left out. Why do you think they left it out. Obviously this wasn't a documentary at all. This was a defense piece. It was generated by and for Steven Avery by his defense team. It wasn't until netflix decided to repackage this as a documentary that both sides were invited to participate. And so if some of the evidence that was selected, I would call it handpicked or cherry-picked over an 18-month period didn't fit with the narrative or the conclusion that Mr. Avery was the product of a conspiracy or some planting of evidence, it's my belief that the filmmakers just wouldn't include that information. My biggest concern about this whole process was their decision then to call it a documentary. You think Steven Avery should have a new trial? This docudrama I think it's called, itself is not going to form the basis of a new trial. It doesn't matter how much attention it receives, unless there's a legal challenge that comes forth there shouldn't be any reason for a new trial. The flipmakers also included information about you in the documentary. Something we covered in years past that you were forced out of office because of a sexting scandal. Do you think that was relevant and is that why you didn't participate in the film? Well, that part of the case is rather disturbing. They included some problems that I engaged in which were deploreable. There wasn't any excuse for that kind of behavior but they happened three years after the conclusion of the Avery case and so the relevance didn't make any sense to me and really a lot of people that are watched it. They don't have anything to do however with the Steven Avery case. The filmmakers knew that and to include it, I think, was unfair. Finally several hundred thousand people have petitioned president Obama to pardon Steven Avery. What do you say to them? Well, as I understand, the president since it's a state case wouldn't have any pardon opportunity and I doubt that any executive officer whether it's the president or the governor is going to weigh in on this in any substantial way. It's unfortunate, however, that the victim's family really has to go through questions and this kind of nonsense that law enforcement is responsible for the death of their family member rather than those that were convicted of the crimes. Mr. Kratz, thanks for your time this morning. All right. George, have a good day. He's right about that. The president really has no grounds for stepping in here. A lot of people are talking about this documentary.
This transcript has been automatically generated and may not be 100% accurate.