HUDSON, WIS. - With fewer than six months to go before Aaron Schaffhausen goes on trial for killing his three young daughters in July, a sometimes-contentious pretrial hearing Wednesday foreshadowed the complex legal battle to come.

Arguments on procedural issues in what is already an emotion-charged murder case, particularly between defense attorney John Kucinski and St. Croix County Circuit Judge Howard Cameron, often became heated but were revelatory -- including the possibility that an insanity plea could be entered.

Prosecutor Gary Freyberg, an assistant attorney general handling the case because of its complexity, also suggested for the first time that Schaffhausen's motive was "to do as much harm to his wife as he possibly could."

As arguments swirled about him, Schaffhausen, shackled at the waist and ankles, never moved or spoke.

Schaffhausen, 35, was charged July 12 with three counts of first-degree intentional homicide for the deaths of his daughters, 11-year-old Amara, 8-year-old Sophie and 5-year-old Cecilia.

Authorities also found a gas fireplace turned on and gasoline poured in the basement of the River Falls, Wis., home, prompting an additional charge of arson.

Schaffhausen, a divorced carpenter living in Minot, N.D., shared legal custody of the girls, who lived with their mother, Jessica. He had been fired when, according to a criminal complaint, he called and texted his ex-wife around noon on July 10, saying he was nearby and asking to spend time with the children at the family home. She agreed but told him he had to leave the house by 3:30 p.m., before she got home, the complaint says. A baby sitter said the girls were excited to see him and led him upstairs to show him their things, the document says. The baby sitter left and at 3:30, Jessica Schaffhausen told police, she got a call from her ex-husband telling her he had killed the children. "You can come home now, because I killed the kids."

Aaron Schaffhausen faces the possibility of life in prison on each intentional homicide charge.

Concerns over timing of plea

Much of the two-hour hearing focused on preparations for possibly entering a plea of not guilty by reason of insanity. That plea would set up a two-phase trial, the first to determine whether Schaffhausen committed the crimes, then one to ascertain his state of mind.

Freyberg, anticipating the possibility of the plea, wanted to have Schaffhausen examined soon, given that the process can take three months. But Kucinski resisted, saying the issue is premature.

Cameron, trying to keep the trial on schedule, said he "didn't want to get to February and all of a sudden have a [not guilty by reason of insanity] plea."

Kucinski replied he wouldn't come to the court on such short notice with a plea. "I get that. I'm not retarded," he said, adding he was frustrated about the pace with which prosecutors were sharing key forensic evidence.

Cameron set a deadline of Dec. 14 for Kucinski to notify the court if a motion for an insanity plea will be made, so that prosecutors can respond. The plea can always be withdrawn later, the judge added.

Freyberg also argued to have horrific crime scene photos and other evidence gathered at the murder scene sealed. Without elaborating, he said he feared Schaffhausen would release the evidence to punish his wife. He said the records should be sealed "so that he cannot continue to destroy her life." The request was approved.

Cameron also set a series of deadlines for issues such as whether to change the venue of the trial because of adverse publicity in the case and whether cameras will be allowed in the courtroom.

'You can tell me anything'

When Cameron set deadlines for preparing lists of lay witnesses and expert witnesses, Kucinski again chafed.

Tensions rose between Cameron and Kucinski when the judge, trying to stay on schedule, set a deadline for preparing the lists of witnesses.

"You can tell me anything, but I'm telling you: It isn't going to happen," Kucinski said, in one of several protests.

"You know what you have to do," Cameron responded. "Get on it."

When Cameron set a date of Dec. 28 to prepare arguments to change the trial venue, Kucinski snapped: "If I can't do it, I'll be blunt: I'm going to stand up in court and say I've been an ineffective counsel." Such a declaration could lead to a mistrial.

The next hearing will be Dec. 3, at which a 3 1/2-hour tape of Schaffhausen's interrogation at the River Falls Police Department will be reviewed, and attorneys will argue what may or may not be seen by jurors.

Jim Anderson • 651-925-5039 Twitter: @StribJAnderson