MADISON, Wis. — A Wisconsin inmate featured in the Netflix series “Making a Murderer” has no basis for his claims that his confession wasn’t voluntary and shouldn’t be released from prison as a judge has ordered, state attorneys argued in a court filing.

Brendan Dassey, now 27, was sentenced to life in prison in 2007 in the death of photographer Teresa Halbach two years earlier. He told detectives he helped his uncle, Steven Avery, rape and kill Halbach in the Avery family’s Manitowoc County salvage yard.

A federal magistrate judge overturned Dassey’s conviction in August, ruling investigators coerced Dassey into confessing. The judge agreed with Dassey’s arguments that detectives promised him leniency and took advantage of his cognitive problems and youth. Dassey was 16 years old at the time of the interrogation.

The state Justice Department has appealed the judge’s ruling to the 7th U.S. Circuit Court of Appeals. A team of attorneys from the state Justice Department, including Attorney General Brad Schimel, Solicitor General Misha Tseytlin and Deputy Solicitor General Luke Berg, argued in brief filed Wednesday that Dassey’s claims have no grounds.

The detectives didn’t offer Dassey any specific benefits for his confession, the attorneys wrote, and the investigators exerted far less pressure than in many other juvenile confessions that the appeals court has upheld. As for his cognitive problems, Dassey attended mostly regular-track high school classes and he resisted many of the detectives’ questions, the brief said.

Dassey also gave detectives details they never suggested, including colors and sounds from the scene in the salvage yard, including Halbrach’s screams, conversations, timing of events and his motivations, the filing said. Taken together, those details suggest the confession was probably voluntary and true, the attorneys wrote.

Dassey’s attorneys didn’t immediately respond to an email Thursday seeking comment on the filing.

Avery was sentenced to life in prison in a separate trial. He’s pursuing his own appeal.

Both men claim police framed them because they were angry with Avery after he filed a lawsuit against Manitowoc County over his wrongful imprisonment for a sexual assault he didn’t commit.

Their claims gained attention last year after Netflix aired “Making a Murderer,” a multi-part series examining Halbach’s death and the Avery family.

“Making a Murderer” prompted widespread conjecture about the pair’s innocence and sparked a torrent of angry online postings demanding prosecutors set them free. Authorities who worked on the cases say the series was biased.