"My name is Ken Kratz. You may know me as the chief villain in the Netflix docuseries Making a Murderer ."

So begins a forthcoming book by the lead prosecutor on the Steven Avery case. The popular Netflix series presented the argument that the justice system had failed Avery and his nephew Brendan Dassey when they were convicted in the killing of 25-year-old Teresa Halbach. The filmmakers showed various ways that the detectives and prosecutors who were involved—including Ken Kratz—may have made mistakes in the investigation and prosecution. Viewers ate it up, and the show became an instant sensation, 10 years after the young woman died. Now, Kratz tells his side of the story in Avery: The Case Against Steven Avery and What Making a Murderer Got Wrong , a point-by-point counterargument to the series (with a foreword by Nancy Grace ) that will be published on Feb. 21.

Kratz writes that he received more than 4,000 death threats and hate messages after the show aired. "Men wrote that they wanted to rape and kill my daughter while I was forced to watch," he writes. "Fortunately, I don't have a daughter." The hatred stemmed not only from his involvement in the prosecution, but also from his unrelated misdeeds mentioned in the show: "sexting a domestic abuse victim, and making inappropriate advances toward other women," he writes. "If you judge me harshly, I don't blame you. Rest assured, my punishments fit my crimes. I lost everything: my wife, my career, my house, my life savings, and my reputation. After inpatient rehab for sex addiction, I've been 'clean' for more than six years. Yet even today, I'm defined by my regrettable past."

Kratz, who declined to participate in the Netflix series, still believes that Avery and Dassey were guilty, but he tries to understand why the show was so persuasive to viewers:

"Timing and technology, I thought, underpinned Making a Murderer 's success. The show burst out during an electric, transformative, pre-Trump period in our country. Notoriously conservative America seemed to be leaning left, newly willing to challenge law enforcement. Many of the police shootings that fueled the Black Lives Matter movement resulted in no charges being filed against cops (think Baltimore , Ferguson), and yet the American public clamored for the freedom of a white man, Steven Avery, who was, by any measure of the evidence, stone guilty. This fascinated and, frankly, surprised me. When Making a Murderer took home four Emmys, it seemed that those who judge popular culture had sanctioned a newfound activist spirit, if one inconsistently applied."

One of the most titillating moments in the series came when the defense team found the vial of Steven Avery's blood had a tiny hole in the lid, and that tape around the box containing it had been sliced. Both findings seemed to support the idea that blood could have been removed from the vial and planted on the crime scene to frame Avery. Attorney Jerry Buting called it a "red-letter day" for the defense. But Kratz, who has spoken out about this evidence previously, says there are simple explanations for both circumstances.

"We see close shots of the broken seal on the box that contains the vial of blood. We do not hear that the seal was broken in the presence of Avery's own Innocence Project defense team in 2002, in a meeting to review the available physical evidence for retesting in pursuit of his eventual exoneration." Additionally, he writes, "We do not hear that the hole in the top of the tube was actually made by a nurse when the blood was first collected from Steven Avery, not by some phantom police conspirator. This is how all blood gets into collection tubes , as you are probably aware if you have ever had blood drawn yourself."

Dassey, Avery's accused accomplice, had his conviction overturned by a lower court in August , after his defense argued that his confession had been coerced. He remains in prison while the state appeals the decision (and Netflix plans to air additional episodes on the post-conviction process for both men). But Kratz says he stands by the original prosecution:

"I lose no sleep over my prosecution of Brendan Dassey. I was a prosecutor with a dead young woman and her surviving family for which to pursue justice. It was not my fault that Brendan was easily manipulated by Avery, or had a low IQ, or was shy, or that he made a dozen inconsistent statements. I believe Brendan could have saved Teresa's life, but chose instead to involve himself in the rape, murder, and mutilation of an innocent woman. I have always said that he did not deserve life in prison, and should have taken the plea bargain that I offered him. But I couldn't, and can't make Brendan's choices for him."

After his sexting scandal and the docuseries, Kratz made a number of life changes, moving house and making it more difficult for harassers to find him. "Life is slow, but intentionally so these days," he writes. "I subscribe to Netflix."