By Kevin Lessmiller/Courthouse News

(CN) – Attorneys for Wisconsin filed a brief Thursday with the U.S. Supreme Court, asking the justices not to hear “Making a Murderer” subject Brendan Dassey’s appeal of his rape and murder charges at the center of the Netflix documentary series.

The brief, filed by lawyers with the Wisconsin Department of Justice, argues Dassey’s controversial confession was voluntary and that investigators used only standard interrogation techniques.

Dassey, a 16-year-old with “intellectual deficits” at the time of his interrogation and arrest, was convicted of assisting his uncle, Steven Avery, in the brutal rape and murder of Teresa Halbach in 2005. Halbach’s bones were found charred in a burn pit near Avery’s home.

There was no DNA or other physical evidence linking Dassey to the crime, and his conviction rested solely on his confession.

A documentary series called “Making a Murderer” released on Netflix’s streaming service strongly suggests the pair were wrongfully convicted so that rural Manitowoc County could avoid paying a large settlement following Avery’s exoneration for a different crime. Avery served 18 years in prison for a rape he never committed, and had filed a $36 million civil suit against the county.

The series generated new interest in the 11-year-old case, including harsh criticism of the investigators who questioned Dassey without a parent or lawyer present and allegedly promised lenience that never came. Dassey was sentenced to life in prison for rape and murder with no possibility of parole until 2048.

U.S. Magistrate Judge William E. Duffin reversed his conviction in 2016 finding the interrogator’s “false promises” and suggestive interrogation techniques, combined with Dassey’s age, inexperience and intellectual disabilities, rendered his confession involuntary.

After initially affirming the reversal, the en banc Seventh Circuit ruled 4-3 in December that Dassey’s conviction should stand.

Dassey’s attorneys filed a petition for writ of certiorari with the nation’s high court in February, asking it to decide whether the Wisconsin Court of Appeals was wrong to find that a confession made by a juvenile “with significant intellectual and social limitations” was voluntary.

On Thursday, Wisconsin Department of Justice attorneys urged the nation’s highest court not to hear Dassey’s appeal.

“The Wisconsin Court of Appeals correctly articulated this Court’s totality-of-the-circumstances standard for voluntariness and reasonably applied that standard to the facts,” the 45-page brief states.

The state claims investigators asked Dassey’s mother for permission to question him and read him his Miranda rights.

“Throughout the three-hour, noncustodial interview, investigators used only standard techniques such as adopting a sympathetic tone, encouraging honesty, and challenging his story when they believed he was lying,” the brief states.

It continues, “Less than an hour in, petitioner unexpectedly confessed to investigators that, at his uncle’s urging, he had raped the victim while she was tied up in bed and begging for mercy, and soon thereafter confessed to helping kill her and burn her body. Petitioner now asserts that investigators fed him this confession, but the only plausible source for his admissions was his guilty conscience.”

Top photo – In this April 16, 2007, file photo, Brendan Dassey appears in court at the Manitowoc County Courthouse in Manitowoc, Wis. Dassey is a Wisconsin inmate who was featured in the “Making a Murderer” series about the 2005 rape and murder of Teresa Halbach. (Dan Powers/The Post-Crescent, Pool, File)