MADISON, Wis. — Wisconsin prosecutors on Thursday charged the father of a teenage girl who killed a teacher and fellow student in a school shooting last year with allowing her access to the semiautomatic pistols she used in the attack.

The video in the player above is from a previous report.

The criminal complaint against 42-year-old Jeffrey Rupnow of Madison details how his daughter, 15-year-old Natalie Rupnow, struggled with her parents’ divorce, showing her anger in a written piece entitled “War Against Humanity.” Her father tried to bond with her through guns, the complaint said, even as she meticulously planned the attack, including building a cardboard model of the school and scheduling the shooting to end with her suicide.

Jeffrey Rupnow was arrested early Thursday and taken to the Dane County Jail. He was scheduled to make his initial court appearance Friday. Online court records did not list an attorney for him. Acting Madison Police Chief John Patterson said he was cooperative throughout the investigation. No one returned voicemails left at possible telephone listings for him and his ex-wife, Melissa Rupnow.

Attack left 2 dead, 6 injured

Natalie Rupnow entered Abundant Life Christian School, a religious school in Madison that offers prekindergarten through high school classes, on Dec. 16 and opened fire in a study hall. She killed teacher Erin Michelle West and 14-year-old student Rubi Bergara and injured six others before she killed herself.

According to the complaint, investigators recovered 20 shell casings from the study hall where she opened fire.

They also recovered a 9 mm Glock handgun that Jeffrey Rupnow had purchased for her from the room and a .22-caliber Sig Sauer pistol from a bag the girl was carrying, the complaint says. Jeffrey Rupnow had given that gun to her as a Christmas present in 2023, the complaint says.

Also in the bag were three magazines loaded with .22 ammunition and a 50-round box of 9 mm ammunition. She wore a black T-shirt emblazoned with a bull’s-eye during the attack.

Natalie Rupnow had been struggling with parents’ divorce

Jeffrey Rupnow told investigators that his daughter lived with him but had been struggling with his divorce from her mother in 2022, saying she hated her life and wanted to kill herself. He said she used to cut herself to the point where he had to lock up all the knives in his house.

She had been in therapy to learn how to be more social until the spring before the attack, he told investigators. Her mother, Melissa Rupnow, told detectives that the therapist told her that Natalie was suffering post-traumatic stress disorder stemming from the divorce. One of Natalie’s friends told investigators that Jeffrey Rupnow was “frequently verbally aggressive” with Natalie and that she had told him that her father was a “drinker,” according to the complaint.

Jeffery Rupnow told investigators that took Natalie shooting with him on a friend’s land about two years before the Abundant Life attack. She enjoyed it, and he came to see guns as a way to connect with her. But he was shocked at how her interest in firearms “snow balled,” he told investigators.

He kept Natalie’s pistols in a gun safe, telling her that if she ever need them the access code was his Social Security number entered backward. About 10 days before the school attack, he texted a friend and said that Natalie would shoot him if he left “the fun safe open right now,” according to the complaint.

The day before the school attack he took the Sig Sauer out of the safe so Natalie could clean it. But he got distracted and wasn’t sure if he put the weapon back in the safe or locked it, according to the complaint.

‘War Against Humanity’

A search of Natalie’s room netted a six-page document the girl had written entitled “War Against Humanity.” She started the piece by describing humanity as “filth” and saying she hated people who don’t care and “smoke their lungs out with weed or drink as much as they can like my own father.”

She wrote about how she admired school shooters, how her mother was not in her life and how she obtained her weapons “by lies and manipulation, and my fathers stupidity.”

Investigators also discovered maps of the school and a cardboard model of the building, along with a handwritten schedule that detailed how she would being the attack at 11:30 a.m. and wipe out the first and second floors of the school by 11:55 a.m. She planned to end the attack by 12:10 p.m. with a notation “ready 4 Death.”

She had been communicating online with people around the world about her fascination with school shootings and weapons, Acting Madison Police Chief John Patterson said Thursday.

Father calls teaching her gun safety ‘biggest mistake’

Jeffery Rupnow sent a message to a detective two weeks after the school shooting saying that his biggest mistake was teaching Natalie how to handle guns safely and urging police to warn people to change their gun safe combinations every two to three months, the complaint said.

“Kids are smart and they will figure it out,” he wrote. “Just like someone trying to hack your bank account. I just want to protect other families from going through what I’m going through.”

According to the complaint, after learning that Natalie was the shooter while talking to a police officer, Melissa Rupnow began breathing very quickly through her nose and yelled something, to the effect of, “I’m going to kill him, I’m going to kill him,” apparently referring to her ex-husband.

Charges are latest in string of cases against parents in school shootings

Jeffrey Rupnow is the latest parent of a school shooter to face charges associated with an attack.

Last year, the mother and father of a school shooter in Michigan who killed four students in 2021 were each convicted of involuntary manslaughter. The mother was the first parent in the U.S. to be held responsible for a child carrying out a mass school attack.

The father of a 14-year-old boy accused of fatally shooting four people at a Georgia high school was arrested in September and faces charges including second-degree murder and involuntary manslaughter for letting his son possess a weapon.

In 2023, the father of a man charged in a deadly Fourth of July parade shooting in suburban Chicago pleaded guilty to seven misdemeanors related to how his son obtained a gun license.