The trial of the man accused of killing his three daughters inside their River Falls, Wis., home last summer, begins Monday with jury selection in St. Croix County Circuit Court.
Last week, Aaron Schaffhausen admitted guilt on three counts of first-degree intentional homicide and one of attempted arson.
He's accused in the July 2012 killings of his daughters 11-year-old Amara, 8-year-old Sophie and 5-year-old Cecilia.
His defense hinges on the fact that he's not responsible for his actions due to mental illness.
Defense attorneys will have to convince 10 of 12 jurors that, because of a mental disease or defect, Schaffhausen lacked substantial capacity either to appreciate the wrongfulness of his conduct or to conform his conduct to the law, the Star Tribune reports.
The newspaper notes that Wisconsin legal experts have said it’s a difficult claim to win.
The trial won’t last as long as first thought, and certain graphic evidence may not be a part of the proceedings, WCCO reports.
Trial evidence is expected to include testimony from the girls' mother, Jessica Schaffhausen, and a recording of the 40-minute 911 call she made to police in River Falls, FOX 9 reports.
Lead defense attorney John Kucinski has said he could call 20 witnesses to the stand, and that the trial could last two weeks or so, KARE 11 reports.
If a jury finds Schaffhausen understood the wrongfulness of his crimes, he could face three consecutive life sentences, or at the least, 60 years, KARE 11 reports.