HUDSON, Wis. (AP) -- Police found a horrifying scene at the Schaffhausen family home in the western Wisconsin city of River Falls last July: three girls dead in their beds, their throats slashed. In the basement, gasoline was sloshed in a possible attempt to burn down their mother's house.
This week, the girls' father goes on trial to determine whether he was insane at the time. Aaron Schaffhausen last week conceded guilt on three counts of first-degree intentional homicide and one of attempted arson, but maintained that he's not responsible for his actions due to mental illness.
Prosecutors argue Schaffhausen was perfectly aware of what he was doing, and killed 11-year-old Amara, 8-year-old Sophie and 5-year-old Cecilia because he was still bitter about their divorce and furious because he thought she had begun seeing another man. Their evidence, according to a criminal complaint, includes a chilling statement to his ex-wife right after the killings: "You can come home now because I killed the kids."
Jury selection begins Monday in St. Croix County Circuit Court. 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, a community of about 15,000 people about 30 miles east of the Twin Cities.
For Schaffhausen, the stakes are likely the difference between spending the rest of his life in prison, if he's judged sane, or being committed to a psychiatric institution from which he might someday be released.
"Our office, as well as the attorney general's office, has put a lot of time into this case, a lot of resources, and I believe we're both prepared," District Attorney Eric Johnson said.
Schaffhausen's public defender, John Kucinski, spent months refusing to concede his client killed the girls. He fought hard in pretrial proceedings to exclude as much damaging evidence as possible, often unsuccessfully, ahead of last week's plea change.
Even though the focus has shifted to Schaffhausen's mental state, the lead prosecutor, Assistant Attorney General Gary Freyberg, said he'll present much of the same evidence he had planned to use to prove guilt because he said it shows Schaffhausen understood what he was doing.
Aaron and Jessica Schaffhausen divorced in January 2011. Court papers indicate their marriage had been rocky for several years, and her mother told police the last straw was when Jessica discovered he was lying about having gone back to school. Her mother told police he either flunked out or dropped out, and kept it secret for several months, until it was too late to get a refund. Jessica and the girls stayed in the house in River Falls. Aaron took a construction job in Minot, N.D.
According to the complaint, Aaron Schaffhausen texted his ex-wife July 10, 2012, to ask for an unscheduled visit with the girls. She consented but said he had to be gone before she got home because she didn't want to see him. The girls' babysitter told investigators the children were excited when he arrived. The babysitter left. He called his wife about two hours later to say he'd killed their children.
Police arrived to find the girls lying in their beds, their blankets pulled up to their necks. White t-shirts were tied around their necks.
"All were found with their throats cut widely and deeply," prosecutors said in court filings. They said the "vast majority" of the blood at the scene was found in Cecilia's room, indicating he killed them there, and then tied the shirts around his girls' necks in an attempt to keep their blood off his own clothes as he carried the other children to their bedrooms. Only Cecilia showed signs of strangulation, they wrote.
Winning with an insanity defense is usually an uphill battle, though the legal test in Wisconsin is somewhat easier than in other states. Wisconsin requires at least 10 of the 12 jurors to find the evidence shows a defendant suffered from a "mental disease or defect" so great at the time that he or she "lacked substantial capacity either to appreciate the wrongfulness of his or her conduct or conform his or her conduct to the requirements of law."
Few details have emerged publicly on Schaffhausen's mental state since the girls were killed. He's been evaluated by experts for the prosecution, the defense and the court. Much of that information remains under seal. In a February filing, prosecutors said the defense had not spelled out Schaffhausen's mental defect or how it affected his actions.
Kucinski offered a hint in pretrial proceedings last week, however, when he said the prosecution expert concluded that Schaffhausen suffers from a "major depressive order." He did not elaborate.