CHICAGO (AP) — A full federal appeals court has heard arguments about whether investigators coerced a confession from a Wisconsin inmate featured in the “Making a Murderer” series. If they rule he was coerced, he could go free.

Several judges at the 7th Circuit U.S. Court of Appeals in Chicago on Tuesday appeared sympathetic to arguments that investigators manipulated Brendan Dassey’s into saying what they wanted him to say. The appeals court has seven judges.

Dassey was sentenced to life in prison in 2007 after telling detectives he helped his uncle, Steven Avery, rape and kill photographer Teresa Halbach.

Judge Diane Wood said watching a video showing how investigators questioned Dassey made her “skin crawl.” She said they fed him answers. But Diane Sykes and several other judges sounded unconvinced that investigators went too far.

A ruling is expected within several weeks.