(Reuters) - Investigators were still working on Wednesday to determine why a teenage girl opened fire two days ago at her private Christian school in Madison, Wisconsin, killing a fellow student and a teacher before taking her own life.
The shooter, Natalie Rupnow, 15, was found dead by responding officers at Abundant Life Christian School around 11 a.m. on Monday, according to police.
"Identifying a motive is our top priority, but at this time it appears that the motive was a combination of factors," Madison Police Chief Shon Barnes told a press conference, without providing additional details.
The suspect is an outlier in at least one way: women and girls are far less likely to carry out school and mass shootings than male suspects. Among the 2,610 incidents since 1966 tracked by the K-12 School Shooting Database in which the gender of the shooter is listed, female suspects were responsible for only 107, or about 4%.
Police are scouring Rupnow's online activity, checking her cell phone and interviewing her friends and family to try to understand her motivations, including whether she was a victim of bullying. They are also examining a manifesto purportedly written by her before the attack to determine its veracity.
Two students were still in critical condition late on Tuesday, while four others suffered less serious wounds, according to police. The identities of the victims have not yet been publicly released.
On Tuesday evening, hundreds of people gathered at a candlelight vigil to honor the victims.
Authorities are tracing the handgun used in the attack. It is not yet clear how Rupnow gained access to the gun.
A Facebook profile belonging to her father, Jeff Rupnow, posted a photo in August showing his daughter trap-shooting at a local gun club. In a comment on the photo, Rupnow says he and his child joined the club in the spring and "have been loving all every second of it." He could not be reached for comment.
Asked on Tuesday whether the suspect's parents could be held legally responsible, Barnes said thus far it does not appear charges are warranted.
The strategy of holding the parents of school shooters partly responsible for their children's actions appears to be gaining traction among prosecutors.
Earlier this year, the parents of a school shooter in Michigan were found guilty of allowing their son access to the murder weapon. In Georgia, the father of a 14-year-old school shooting suspect was charged with murder and other counts for allegedly buying his son a rifle and ammunition. And in Virginia, the mother of a six-year-old boy who shot a teacher was convicted of state and federal charges for failing to secure the weapon her son used.
Court records in Dane County, Wisconsin, show Rupnow's home life may have been challenging. Her parents married and divorced each other three times after her birth, sharing custody. Her primary residence switched from her mother's to her father's home in July 2022, a year after their final divorce.
In the Facebook photo, the girl is wearing a T-shirt of the German band KMFDM. The teenaged shooters in the 1999 Columbine school massacre in Colorado were known to be avid fans of the band, and one of the killers posted the band's lyrics on his website.
At the time, KMFDM issued a statement condemning the Columbine attack, expressing sympathy for the victims and affirming its music was intended to stand against violence.
School shootings have become a near-daily occurrence in the United States, with 322 of them this year, according to the K-12 School Shooting Database. That is the second highest annual total since 1966, exceeded only by last year's 349.
The repeated violence has fueled the debate over gun control in the U.S. But efforts to tighten firearm laws have made little progress in Congress, where Republicans argue that such limits would violate the U.S. Constitution's guarantee of the right to bear arms.
(Reporting by Rich McKay in Atlanta and Joseph Ax in Princeton, New Jersey; Editing by Nick Zieminski)