Brenda Dassey, one of the subjects of the Netflix documentary series “Making a Murderer,” has been denied clemency after serving 13 years of a life sentence in prison following conviction for aiding in the murder of Teresa Halbach.

This week, Wisconsin Governor Tony Evers rejected a request for a reprieve made by Dassey’s legal team in October that included an audio interview with Dassey for a podcast about wrongful convictions. In addition to a petition that was signed by tens of thousands of supporters, the legal team also submitted an open letter to the governor that included the signatures of hundreds of legal and psychological experts, former police officials, and prosecutors and clemency experts, Dassey lawyer Laura Nirider told The New York Times on Saturday.

In an unsigned letter dated Dec. 17, the governor’s pardon advisory board wrote that Dassey was ineligible for clemency and that the governor would not consider any commutations.

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“Specifically,” the letter says, “you are currently ineligible because: It has not been at least five (5) years since you completed your entire sentence for the conviction you want to be pardoned; You are currently required to register as a sex offender under Wis. Stat. § 301.45.”

Dassey was 16 when he confessed to aiding his uncle Steven Avery in killing Halbach. However, his attorneys have since seen it as a coerced confession given Dassey’s learning disabilities. At the time of the interrogation, no lawyers or other adults were present. The Netflix series “Making a Murderer” chronicled the trials and convictions of both him and his uncle, Steven Avery.

In December 2018, the 7th U.S. Circuit Court of Appeals decided that Dassey’s confession was voluntary. It was a tight vote, however, with a 4-3 outcome. Lower courts ruled that Dassey’s confession was involuntary. In June of last year, the Supreme Court of the United States declined to hear his case, but no reason was given. Dassey is currently serving a life sentence. At this time, Dassey is not eligible for parole until 2048, when he would be 59 years old.