MINNEAPOLIS (WCCO) — A Wisconsin father accused of killing his three young daughters has delayed a possible guilty plea for at least day.

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Aaron Schaffhausen was expected to plead guilty and also plead insanity in a move that could allow him to be sent to a state mental hospital and eventually released.

The hearing to potentially change Schaffhausen’s plea was rescheduled for Thursday at 1 p.m. by St. Croix County Circuit Judge Howard Cameron.

For the first time since the murder of 11-year-old Amara, 8-year-old Sophie and 5-year-old Cecilia, the girls’ mother Jessica Schaffhausen was in court for what was expected to be a guilty and insanity plea by her ex-husband.

If Aaron Schaffhausen enters that plea on Thursday, there will be a jury trial to determine his sanity and Jessica Schaffahausen will be the state’s key witness.

Court documents say Aaron Schaffhausen called up his ex-wife when she was at work and asked to visit his girls. When he got to the River Falls home, he let the baby sitter go.

A short time later Jessica Schaffhausen said her ex called her and said, “You can come home now I killed the kids.”

The prosecution is expected to argue that shows Aaron Schaffhausen planned the killings and is sane. The defense said a prosecution expert will testify he is mentally ill.

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“That witness found he did suffer from a major depressive disorder,” Defense Attorney John Kucinski said.

Prosecutor Gary Freyberg objected.

“If we go into this level of detail, it should be in a closed proceeding,” he said.

Aaron Schaffhausen sat emotionless throughout Wednesday’s hearing. Prosecutor Freyberg made it clear he will try to avoid introducing graphic evidence of the murder scene.

“We might still out of a number of considerations decided to use the diagrams, instead of the photographs,” he said.

In a letter written to Schaffhausen’s attorney on Tuesday, prosecutors wanted to make sure Schaffhausen was aware that a plea change won’t keep certain evidence from being heard.

He faces three counts of first-degree intentional homicide, and back on March 1, he had entered a plea of not guilty by reason of insanity.

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Regardless, the trial will start on Monday — and will either be focused on determining Aaron Schaffhausen’s guilt or innocence or if he does change his plea, will try and determine whether he is insane.