– The man accused of killing his three daughters in their River Falls home had threatened his ex-wife and another man and yelled at his former mother-in-law in the months before the girls died in July, prosecutors alleged in court Friday.

Attorneys debated just how much evidence of such threats and the couple’s troubled marriage and messy divorce jurors should be allowed to hear at trial, set to begin April 1.

Aaron Schaffhausen, 35, faces three counts of first-degree intentional homicide in the deaths of 11-year-old Amara, 8-year-old Sophie and 5-year-old Cecilia. He entered an insanity plea in January.

Defense attorneys argued that alleged threats — including a phone call and Facebook postings to another man — should be excluded from trial, as well as evidence of him shouting at his former mother-in-law because they occurred months before the crime and were irrelevant.

Prosecutor Gary Freyberg disagreed, saying Schaffhausen believed the man was stealing his family and his threats spoke to the extent, duration and intensity of Schaffhausen’s anger at Jessica Schaffhausen, and “why he would want to ... ‘make her suffer,’ in his words.”

Freyberg also argued that evidence starting in 2011, the year their divorce petition was filed, will show Aaron Schaffhausen’s growing rage.

“The defendant made a number of statements to her about his intention to do exactly what he ended up doing. ... He made a number of statements to her about his jealousy, his anger, his rage, his bitterness, his possessiveness,” Freyberg said. But, he argued, evidence of prior arguments during the couple’s marriage would waste the jury’s time.

“It appears that the defendant is going to want to somehow blame Jessica Schaffhausen for this,” Freyberg said. “I don’t think that’s appropriate. It’s not relevant, and it’s not true.”

Defense attorney John Kucinski argued that if prosecutors are allowed to show Schaffhausen was jealous and possessive, then jurors should also hear about what led up to that on his ex-wife’s part.

Schaffhausen yelling at his former mother-in-law “has nothing to do with any intent or motive to kill three children four months later,” said defense attorney Donna Burger.

Judge Howard Cameron said he will allow evidence of threats made to the man and yelling at Schaffhausen’s former mother-in-law, but he reserved judgment on evidence of the couple’s troubled marriage before 2011.

Cameron also ruled that cameras will be allowed in the courtroom for the trial, which is expected to include more than 100 witnesses and take at least three weeks. His insanity plea sets up a two-phase trial. If found guilty of the crimes in the first phase, a second phase would determine whether he is mentally responsible.

The court has reserved space for jury selection at a Hudson golf club with a room big enough to handle the jury pool. Cameron said notices were sent to 200 potential jurors and 33 have been excused so far.

Freyberg said he expects Jessica Schaffhausen to attend the trial only to testify.