By Sharon Bernstein

(Reuters) - A federal judge in Wisconsin on Wednesday denied a motion aimed at stopping the release of Brendan Dassey, who was imprisoned for life for helping his uncle kill a freelance photographer in 2005 in a case spotlighted in the Netflix documentary "Making a Murderer."

Dassey, now 27, and his uncle, Steven Avery, were convicted in separate trials of killing photographer Teresa Halbach at Avery's home in Manitowoc County, Wisconsin. Halbach's charred remains were found in an incineration barrel and a burn pit on Avery's property, about 80 miles (130 km) north of Milwaukee.

Dassey was convicted at 17 of first-degree intentional homicide, second-degree sexual assault and mutilation of a corpse. Avery was found guilty of first-degree intentional homicide and being a felon in possession of a gun. Dassey was sentenced by the court to life in prison.

The case was the subject of the 10-part Netflix-released documentary "Making a Murderer," which questioned the handling of the investigation and the motivation of Manitowoc County law enforcement officials.

The documentary, which began filming 10 years ago, recounts how Avery was convicted of an earlier, unrelated rape and sent to prison in 1985, serving 18 years before DNA evidence exonerated him and he was released.

In 2005, Avery, and teenaged nephew Dassey, who was learning-disabled, were arrested and later sentenced to life in prison for the killing of Halbach on their rural scrap car property near Manitowoc.

In August, Magistrate Judge William Duffin of the Eastern District of Wisconsin ruled the guilty verdict returned by a trial jury in 2007 against Dassey was based on a coerced confession he gave as a 16-year-old youth with a learning disability.

On Monday, he ordered Dassey's release, and on Wednesday denied a request by prosecutors that the release be delayed. Wisconsin Attorney General Brad Schimel said Wednesday that he would appeal Duffin's ruling.

Schimel had argued that Dassey should remain in custody pending an appeal, saying that Duffin did not have authority to release the 27-year-old. In his motion requesting a stay of Dassey's ordered release, filed Tuesday, Schimel also argued that Dassey's confession was not coerced and that there was considerable evidence showing that he was guilty of the crimes of which he was convicted.

On Wednesday, Schimel filed an appeal of Duffin's refusal to grant the stay and asked the U.S. Court of Appeals for the Seventh Circuit in Chicago to rule before Dassey's scheduled release date on Friday, Nov. 18.

An attorney for Dassey was not immediately available for comment.