Steven Avery appeal: Legal brief delayed until motion by attorney is resolved

The brief that was expected to be filed Monday by Steven Avery's attorney in the state court of appeals has been delayed until a motion is addressed.

Chicago-area attorney Kathleen Zellner filed a motion to correct or supplement the record on May 15. The Wisconsin Department of Justice has until May 29 to file a response before the court reviews it.

The court has previously granted two extensions to file the brief.

Zellner is challenging a ruling by Sheboygan County Circuit Court Judge Angela Sutkiewicz that Avery had not met the legal standard to receive a new trial.

Avery and his nephew, Brendan Dassey, were convicted in the 2005 homicide of 25-year-old photographer Teresa Halbach in Manitowoc County. Both are fighting their convictions and related life prison sentences. The cases were the focus of the popular Netflix docu-series "Making a Murderer," which was released in December 2015. 

Once Avery's brief is filed, the Wisconsin Department of Justice will have an opportunity to file a response brief. The appeals court will eventually issue a ruling, which could be appealed to the Wisconsin Supreme Court.

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Dassey's attorneys have meanwhile asked that the U.S. Supreme Court hear his case. They argue his confession was involuntary and coerced, an assertion against which the Wisconsin Department of Justice has pushed back hard.

The Wisconsin Department of Justice asked the high court to deny Dassey's petition for review. 

Four Justices must vote to grant the petition.