CNN WIRE — Investigating the Madison, WI, school shooter: VIDEO

By Dakin Andone, CNN

(CNN) — Police have identified the shooter in Monday’s deadly attack on a Madison, Wisconsin, private Christian school as a 15-year-old female student as they investigate the latest school shooting to devastate an American community.

Natalie Rupnow – who went by Samantha – was found dead when officers responded to Abundant Life Christian School. Evidence suggests she died of a self-inflicted gunshot wound, Madison Police Chief Shon Barnes said at a news conference late Monday.

A staff member and another student were killed in the attack, while six others were injured, police have said, including two students hospitalized in critical condition.

While the victims recover, authorities are examining Rupnow’s background, probing writings allegedly connected to her and tracing the history of the gun she used.

Here’s what we know:

Motive is authorities’ ‘top priority’

Investigators’ “top priority” is determining the shooter’s motive, Barnes said at a news conference Tuesday afternoon.

“But at this time, it appears that the motive was a combination of factors,” he said, though he declined to provide more details.

Police are speaking to students to determine if bullying was one of the factors, Barnes said.

“Some have asked if people were specifically targeted. Everyone was targeted in this incident, and everyone was put in equal danger,” he added.

Authorities are aware, the chief said, of a “document” that had “been widely shared on social media.”

“At this time we cannot verify its authenticity,” the chief said. “We have detectives working today to determine where this document originated, and who actually shared it online.”

Police are also examining the shooter’s activity online, Barnes told reporters. Officials are not releasing “specifics about these social media accounts,” but he encouraged anyone who knew the shooter or had insight into her feelings prior to the shooting to contact investigators.

It’s relatively rare for a school shooter to be a female: CNN has documented 83 school shootings in 2024, and of the 59 in which the gender identity of the suspected shooter was available, only two were female. The others involved either lone male suspects or a group of male suspects.

The gun

Police have said the shooter used a handgun to carry out the attack – a weapon whose history is now being traced by the Bureau of Alcohol, Tobacco, Firearms and Explosives, Barnes said.

“We have asked our partners with the ATF to expedite what’s called an ATF trace form to try and determine the origin of that weapon, who purchased it and how it got from a manufacturer all the way to the hands of a 15-year-old girl,” Barnes told CNN “News Central” on Tuesday. “These are questions that are going to take some time to answer.”

While it’s not yet clear who owns the gun or where it originated, Rupnow’s father posted a Facebook photo in August of his daughter at a shooting range.

Jeff Rupnow’s cover photo posted in August shows his daughter shooting skeet.

She can be seen wearing a black shirt with the name of the band KMFDM. The German industrial rock band’s lyrics were cited by the students who carried out the 1999 massacre at Columbine High School in Colorado, where 13 people were killed, CNN has reported.

KMFDM issued a statement at the time condemning the 1999 attack and expressed sympathy for the victims, adding their music was intended to stand against violence, according to Reuters.

In a comment on the photo, Jeff Rupnow replied to someone who asked whether the person in the photo is his child, writing, “sure is!!!! We joined NBSC this spring, and we have been loving … every second of it!”

North Bristol Sportsman’s Club (NBSC) is a shooting range in Dane County. CNN has reached out to the group for comment.

Parents are cooperating with investigators

Rupnow’s family is cooperating with police, Barnes said Monday, acknowledging that a heavy police presence at a home on the north side of Madison was related to the shooting.

Rupnow was believed to have had “a turbulent home life,” the Washington Post reported, citing court records it obtained “which show that her parents divorced and remarried multiple times and that she had been enrolled in therapy.” The parents’ custody agreements “sometimes forced her to move between their homes every two or three days,” the newspaper reported.

Neither Jeff Rupnow nor her mother, Mellissa Rupnow, has responded to repeated requests for comment by the Washington Post or CNN.

It’s unclear whether the shooter’s parents owned or possessed the gun used in the shooting, Barnes told CNN. Police, together with the district attorney’s office, will “want to look at if the parents may have been negligent,” he said.

“But at this time, that does not appear to be the case.”

Both federal and Wisconsin law generally make it illegal for someone younger than 18 to possess a firearm. State law similarly makes it illegal for any person to intentionally sell, loan or give a dangerous weapon to someone younger than 18. However, there are exceptions that allow a minor to possess a firearm for target practice under adult supervision, for use in the armed forces or for hunting.

Wisconsin also has a child access firearm law that makes it illegal to recklessly store a loaded firearm within reach or easy access of a child younger than 14.

Prosecutors in recent years have taken steps to hold accountable parents who provided their children the firearms they would go on to use in school shootings, testing the limits of who could be deemed responsible. Two such cases followed school shootings at an Oxford, Michigan, high school in 2021 and a Winder, Georgia, high school in September.

CNN’s Michelle Watson, Eric Levenson, Holly Yan, Sarah Dewberry, Jillian Sykes, Caroll Alvarado, Taylor Galgano and Hanna Park contributed to this report.