Brendan Dassey, one of the subjects of the Netflix series Making a Murderer, has had his conviction for the murder of Teresa Halbach overturned by a federal judge.

Judge ruled that investigators had made false promises during an interrogation

The series, which focused on the murder trial of Dassey's uncle, Steven Avery, also chronicled the prosecution of Dassey, who was convicted of working with Avery in the Halbach murder. The series showed a videotaped interrogation of Dassey in which investigators appeared to lead him toward confessing to the crime, as well as to implicating Avery.

Dassey's family later said he has a low intelligence level and did not understand the interrogation process. An adult guardian was also not present during the interrogation of Dassey, who was 16 at the time. In a later call to his mother featured in the show, he said the confession was invented at the officers' request.

The judge, in making the decision, ruled that a lower court had erred when deciding that investigators made no promises during Dassey's interrogation.

"The investigators repeatedly claimed to already know what happened on October 31 and assured Dassey that he had nothing to worry about," the judge writes in the decision. "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."

Dassey will be released in 90 days unless prosecutors move to retry him. The judge's decision may still be appealed.

In a statement, Making a Murderer directors and executive producers Laura Ricciardi and Moira Demos said that "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."

Netflix recently announced that more episodes of Making a Murder would appear on the service.

Update, 9:19PM ET: Added statement from Laura Ricciardi and Moria Demos.