The judge's order claims the detectives who were investigating Halbach's murder promised Dassey prosecutorial leniency in exchange for his cooperation during his March 1, 2006, interrogation

Making a Murderer's Brendan Dassey to Be Released from Prison as Conviction for Teresa Halbach's Murder Overturned

Brendan Dassey’s conviction for the 2005 murder of Teresa Halbach was overturned by a federal judge on Friday, meaning Steven Avery’s nephew will be released from prison within the next three months.

Court officials confirmed Friday’s decision to exonerate Dassey, who, along with Avery, served as the subjects of the hit Netflix true crime documentary series, Making a Murderer.

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Making a Murderer directors/executive producers Laura Ricciardi and Moira Demos issued the following statement to PEOPLE: “Today there was a major development for the subjects in our story and this recent news shows the criminal justice system at work. As we have done for the past 10 years, we will continue to document the story as it unfolds, and follow it wherever it may lead.”

PEOPLE obtained a copy of Judge William Duffin’s decision, in which he characterized the “misconduct” of Dassey’s first attorney, Len Kachinsky, as “indefensible.”

The judge’s order claims the detectives who were investigating Halbach’s murder promised Dassey prosecutorial leniency in exchange for his cooperation during his March 1, 2006, interrogation.

“The investigators repeatedly claimed to already know what happened on Oct. 31 and assured Dassey that he had nothing to worry about,” the decision reads. “These repeated false promises, when considered in conjunction with all relevant factors, most especially Dassey’s age, intellectual deficits, and the absence of a supportive adult, rendered Dassey’s confession involuntary under the Fifth and Fourteenth Amendments.”

The judge’s decision suggests he had “significant doubts” concerning the reliability of Dassey’s confession.

“Crucial details evolved through repeated leading and suggestive questioning and generally stopped changing only after the investigators, in some manner, indicated to Dassey that he finally gave the answer they were looking for,” the ruling reads. “Purportedly corroborative details could have been the product of contamination from other sources, including the investigators’ own statements and questioning, or simply logical guesses, rather than actual knowledge of the crime.”

Kathleen Zellner, Avery’s new attorney, tells PEOPLE “we are thrilled for Brendan Dassey that his conviction has been overturned,” adding “we fully expected this outcome from an unbiased court that carefully examined his confession.”

According to Zellner, she was just visiting with Avery who “is so happy for Brendan. We know when an unbiased court reviews all of the new evidence we have, Steven will have his conviction overturned as well.”

In March 2006, Dassey, then 16, told investigators he had helped his uncle, Steven Avery, rape and murder photographer Teresa Halbach on Oct. 31, 2005. But he later recanted, claiming the confession had been coerced.

Dassey’s confession to law enforcement is perhaps the most debated aspect of the Netflix series.

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On the day of the confession, lead investigators Tom Fassbender and Mark Wiegert pulled Dassey out of school and questioned him alone for hours.

During that questioning, Dassey told investigators he had helped Avery kill Halbach, saying that they shot her in the head and burned her body at a bonfire on the Avery property later that evening.

Calumet County Prosecutor Ken Kratz called a press conference shortly after investigators secured the confession, saying that Dassey described in detail Halbach’s brutal assault and slaying.

However, after seeing portions of the confession on Netflix, many came to believe he was led by Fassbender and Wiegert, who repeatedly question him until the teen gives them a confession.

In a recorded exchange with his mother, Barb Janda, following the confession, Dassey says, “They got in my head.” The teen later denied that he ever saw Halbach and said he had nothing to do with her murder.

A second season of the Netflix show is in production but the streaming service has provided no information on when the new season will debut.