MADISON, Wis. — A 15-year-old girl who police say killed two people and wounded multiple others at a private Christian school in Wisconsin endured what appeared to be a tumultuous home life marked by divorces, custody battles and a series of court-mandated mediation sessions to resolve disputes over her care, according to court documents obtained by NBC News.

Jeff and Mellissa Rupnow married and divorced twice, during which their daughter Natalie Rupnow would at times travel between her parents’ homes every few days and attend therapy.

They married in 2011 and divorced for the first time in 2014, according to court documents.

The two agreed to joint custody of Natalie, but she would live primarily with her mother, the documents state.

They remarried in 2017, according to their marriage certificate obtained by NBC, but filed for divorce a second time in 2020. Mellissa and Jeff Rupnow again agreed to share custody of Natalie, but this time she would spend “equal time with both parents,” the court documents show. A divorce certificate obtained by NBC News shows their divorce was finalized in 2021.

Natalie Rupnow, who also went by Samantha, shot and killed a teacher and a student and wounded six others during study hall on Monday at Abundant Life Christian School in Madison, Wisconsin, before dying from an apparent self-inflicted gunshot wound, police said. The victims were identified as Erin M. West, 42, and Rubi P. Vergara, 14.

Two students who sustained life-threatening injuries during the shooting remained in the hospital and the other four injured have been discharged, police said.

The FBI detained Alexander Paffendorf, 20, in California earlier this week and ordered him to temporarily surrender his firearms after he allegedly communicated with Natalie Rupnow. Authorities say Paffendorf admitted to discussing plans with Rupnow to arm himself with explosives and target a government building. The FBI uncovered messages between the two but did not disclose their alleged plans.

Paffendorf and his family could not immediately be reached for comment.

The apparent turmoil in Natalie Rupnow’s family life, as documented by court records, offer a glimpse into events that may have shaped her path before Monday’s tragedy.

In 2022, Mellissa and Jeff Rupnow sought mediation for custody of Natalie. That May, Dane County Family Court Services notified the parents of a requirement to attend a “mandatory parent education program via Zoom” due to a “disagreement concerning child custody and/or physical placement.” A month later, according to court documents, Mellissa Rupnow had “been scheduled to attend on June 2nd and June 16, 2022, but did not appear” for the Parent Education Program. Shortly after, the couple was asked to appear for a “mandatory mediation session in person appointment.”

In July 2022, an agreement was reached, granting them joint legal custody of Natalie, who would primarily live with her father, according to court documents. The documents also indicate that the parents agreed to “consider Natalie’s therapist’s recommendations regarding placement” for Natalie during the weekends.

Natalie’s mother agreed to connect with her therapist and “participate in therapy to the extent recommended by the therapist,” according to the court documents. Natalie’s father would make “every effort to schedule therapy appointments” to accommodate the mother’s schedule.

The court documents noted that “the parents report a generally positive co-parenting relationship and will continue to communicate with one another by text messages and phone conversations.”

Jeff and Mellissa Rupnow did not respond to multiple requests for comment. Madison Police Chief Shon Barnes said the two are “fully cooperating” with investigators, who are still trying to identify a motive and have not released many details on the teenager.

“Identifying a motive is our top priority. But at this time, it appears that the motive was a combination of factors,” Barnes said at a news conference.

Trish Kilpin, the director of Wisconsin’s Office of School Safety, said on Monday that “targeted violence is preventable.”

“When somebody decides to use violence, it’s often to redress an upset or a grievance, and they progress down a pathway towards that violence,” Kilpin said. “And when they do that, they often study previous school shooting incidents.”

A neighbor of Jeff Rupnow’s who spoke to NBC News expressed shock when he learned about the shooting and described Jeff as a “kind person.”

“He really helped us out,” said the neighbor, who did not want his name used out of fear of publicity about the case. “I know we’re still trying to piece everything together.”

The neighbor indicated he didn’t know Natalie, saying “the very limited things we knew, it’s horrifying for everyone, obviously, and just horrifying for the families of the school and those kids.”

Selina Guevara reported from Madison, and Chloe Atkins and Daniella Silva reported from New York City.