(Corrects headline, first paragraph to show documentary is titled "Making a Murderer", not "Making of a Murderer")
Feb 20 (Reuters) - A Wisconsin man convicted of murder in the case that was chronicled in the Netflix documentary, "Making a Murderer," on Tuesday asked the U.S. Supreme Court to toss out his 2005 confession that his attorneys claim was coerced by investigators, the Washington Post reported.
Attorneys for Brendan Dassey, 28, made a similar argument to the U.S. 7th Circuit Court of Appeals in Chicago in December and failed. The judges voted 4-3 to uphold his conviction in the slaying of Teresa Halbach.
Dassey confessed when he was 16 of helping his uncle, Steven Avery, rape and kill Halbach, a freelance photographer, in 2005. Her charred remains were found on Avery's property about 80 miles north of Milwaukee in Manitowoc County.
The pair were convicted of the murder in separate trials. Avery is now 55. Both men are in prison in Wisconsin.
The case was the basis for a 10-part documentary, "Making a Murderer," which questioned the handling of the investigation and the motives of Manitowoc County law enforcement officials.
A dissenter in the 7th Circuit Appeals Court decision, Chief Judge Diane Wood, said Dassey was a low-functioning teenager with an IQ in the low 80s, and that without his confession, the case against him was "almost nonexistent."
Wood wrote, "Even if we were to overlook the coercion, the confession is so riddled with input from the police that its use violates due process."
In 2016, a U.S. magistrate judge overturned the guilty verdict against Dassey, citing coercion. Then a three-judge panel of the 7th Circuit upheld the magistrate's ruling, and Wisconsin prosecutors asked for the review by the full circuit.
In October, a Wisconsin judge denied Avery a new trial. (Reporting by Bernie Woodall in Fort Lauderdale, Florida; editing by Simon Cameron-Moore)