A federal judge on Friday overturned Brendan Dassey’s conviction in the death of Teresa Halbach.

The 26-year-old Dassey, who was featured in the Netflix mini-documentary series “Making A Murderer,” was sentenced in 2007 on homicide and sexual assault charges to life without parole over the murder of Halbach in Manitowoc County, Wisconsin.

In the documentary, Dassey appeared as a sympathetic character who seemed to be bullied by investigators during his followup interviews. According to court documents, a federal judge has agreed — stating that investigators made false promises to Dassey and claimed to “already know what happened” when they interrogated him.

The judge rendered Dassey’s confession involuntary under the Fifth Amendment. He’s to be released within 90 days unless the state wants to retry him.

RULING: Federal court finds Brendan Dassey's confession was involuntary under 5th/14th Amendments. #MakingAMurderer pic.twitter.com/yv0496UUDF — Chris Geidner (@chrisgeidner) August 12, 2016

Dassey is the nephew of Steven Avery, a Wisconsin man who was wrongfully convicted of sexual assault and eventually exonerated — only to be convicted of murder years later under suspicious circumstances.

Police obtained what they said was a confession from Dassey, and that formed the basis of much of the prosecution’s case against Avery. At one point in the documentary, Ken Kratz, the prosecutor in the Halbach murder case, describes a supposed timeline of the murder in upsetting detail, and it’s implied that much of the information in that timeline came from Dassey’s detailed account. But in the tape of the actual police interview with Dassey, it looks less like a detailed confession and much more like coercion.

At the time of the interview, Dassey was 16 and did not have an attorney or a parent present. According to court records, Dassey has an IQ of somewhere between 69 and 73 — an IQ of 70 is often considered the threshold for intellectual disability — and the tape shows police posing detailed questions to Dassey, who replies with short, often one-word answers.

Saul Kassin, a psychology professor at the John Jay College of Criminal Justice, told The Huffington Post in an earlier interview that this controversial style of interrogation is called the Reid technique and has led to numerous situations in which an innocent person ends up confessing to a crime they never committed. Teens are especially susceptible to tactics like this.

In an analysis of hundreds of cases going back to 1989, false confessions were found to be one of the leading causes of wrongful convictions, according to the Innocence Project, a nonprofit legal clinic dedicated to exonerating people who have been wrongfully convicted. Overall, about 31 percent of wrongful conviction cases included a false confession, but for homicide cases alone, that number balloons to 63 percent.

In his petition for release, Dassey argued that his attorney had a conflict of interest in the case, that his confession had been coerced by law enforcement and that he was given false promises by investigators. But ultimately, it was the false promises allegation that persuaded Judge William E. Duffin to overturn the conviction.

“[T]he investigators’ collective statements throughout the interrogation clearly led Dassey to believe that he would not be punished for telling them the incriminating details they professed to already know,” Duffin wrote in his ruling. He pointed out that one investigator at one point said rotely “We can’t make any promises...” but that single and isolated statement was “drowned out by the host of assurances that they already knew what happened and that Dassey had nothing to worry about.”

Duffin added a harsh indictment of Wisconsin’s criminal justice system, saying that Dassey’s case represents “extreme malfunction” of the state system.

“Consequently, the court finds that the confession Dassey gave to the police on March 1, 2006 was so clearly involuntary in a constitutional sense that the court of appeals’ decision to the contrary was an unreasonable application of clearly established federal law,” Duffin wrote.

Dean Strang, one half of the defense team for Avery during the “Making a Murderer” series, along with Jerry Buting, said that he and Buting are “relieved and gratified” by the judge’s ruling Friday.

“Brendan’s statements were involuntary ― by the standards of common sense and decency that most Americans apply in their own lives, as well as under binding law that the Wisconsin courts repeatedly failed to apply,” Strang said to The Huffington Post in an emailed statement. “His statements were also wholly unreliable and flatly wrong on essential details, which is one of the obvious risks of coercing a statement from someone in custody. Our federal courts are often the last protectors of our liberties and justice. We are thankful and proud that a federal court fulfilled its fundamental role for Brendan Dassey today. In doing so, this federal court served all Americans.”

Steven Drizin, one of Dassey’s current attorneys, said he and the rest of Dassey’s defense team are “ecstatic” about the ruling.

“This is a huge victory,” he told HuffPost. “But we are taking a wait and see approach to see what the state’s next move will be.”

While Netflix deserves significant kudos for helping to shine the light on the injustices Dassey experienced in the criminal justice system, Stephen Cooper, former D.C. and federal public defender, said that it’s important to remember the “true champions” of Dassey’s “hard-fought and deserved” legal victory today. He said that includes “all of the lawyers, law professors, and students at Northwestern University’s Center on Wrongful Convictions of Youth who filed the successful writ of Habeas Corpus for Brandon Dassey; Magistrate Judge William E. Duffin in Milwaukee who conscientiously applied the rule of law; and our Constitution, which again and again proves why, despite all the many problems we have in the country, we live in a great nation where injustices like Brandon Dassey’s can eventually be righted.”