Updated

Wisconsin's attorney general has asked a federal appeals court to let stand the conviction of a man found guilty in a case profiled in the popular "Making a Murderer" series on Netflix.

A federal magistrate judge ruled in August that investigators tricked Brendan Dassey into confessing he helped his uncle, Steven Avery, rape, kill and mutilate photographer Teresa Halbach in 2005.

In a brief filed with the 7th U.S. Circuit Court of Appeals Wednesday, Attorney General Brad Schimel urged rejection of Dassey's claim that his confession was coerced.

Schimel says "substantial police coercion" is required for any confession to be involuntary, and that the Wisconsin Court of Appeals was right to affirm in 2013 that Dassey's was voluntary. So he says the magistrate's ruling to the contrary should be reversed.