A federal appeals court has blocked the release of Brendan Dassey, one of the subjects in Netflix’s documentary series Making a Murderer, just days after a lower court ordered him to be released from prison.



The decision from a three-judge panel in the seventh circuit court of appeals in the latest development in a years-long legal battle by Dassey to secure his release and overturn his conviction for the 2005 murder of Teresa Halbach, a local Wisconsin photographer.



On Monday, a US magistrate judge, William Duffin, ordered Dassey to be released under court-ordered supervision, three months after having overturned his conviction. Wisconsin’s attorney general, Brad Schimel, immediately announced he planned to file an emergency motion to block Dassey’s release.



In a short order issued on Thursday, the appellate judges stayed Duffin’s decision, pending the outcome of the state’s appeal.



“The district courtʹs order releasing appellee Brendan Dassey is stayed pending resolution of this appeal,” the order stated.



In the emergency motion filed by Schimel, the state argued that Dassey admitted to the crime in “extensive detail”, however Duffin – as well as Dassey’s attorneys – have characterized the confession as “involuntary”.



“This case involves the brutal rape, murder, and mutilation of Teresa Halbach that 16-year-old Brendan Dassey committed with his uncle, Steven Avery,” Schimel wrote. “Dassey admitted to his crimes in extensive detail, in an entirely voluntary confession, during which investigators used techniques that courts around the country have approved time and again.”



Dassey, 27, has been incarcerated since 2007 over the murder of Halbach. Along with his uncle, Steven Avery, the pair were found guilty of Halbach’s murder in separate trials.



The story drew notoriety for Avery’s connection. Before his arrest over Halbach’s murder, he was seen as the face of a US judicial system that can unfairly convict someone: for 18 years, Avery was jailed for a rape he didn’t commit. Eventually, he was exonerated through DNA evidence.



The Netflix series Making a Murderer drew national attention to the Halbach case, particularly for the investigation into Dassey, and what was perceived by his attorneys and Duffin as “indefensible” treatment from his first trial attorney.



Dassey’s current attorney told the Guardian last year that his remarks to police “fit the profile of a [false] confession to an absolute T”. The investigators, for example, suggested he would receive leniency for complying and fed facts “to get Brendan to say how Ms Halbach died”, said the attorney, Laura Nirider.



Duffin agreed. “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 14th amendments,” Duffin wrote in his 91-page ruling.

Duffin cast doubt in his ruling on the state’s chances of success in appealing against his earlier decision to overturn Dassey’s conviction and said there was “no indication” that Dassey “has the inclination much less the means to flee”. He later ordered him released by 8pm on Friday.



“Dassey has offered a detailed release plan that was prepared with the assistance of a clinical social worker with experience in similar cases,” the judge wrote. “That social worker would remain involved in assisting Dassey as he adjusts to freedom following his decade in prison.”



The state countered, saying it has an “extremely high likelihood” of succeeding with its appeal “because the techniques the investigators used here have been approved by numerous courts.”



The Center on Wrongful Convictions of Youth, the legal clinic representing Dassey, said it was disappointed by the decision.



“We are disappointed more than words can say,” the firm said in a statement. “The fight goes on.”