What to know about the 15-year-old suspected school shooter in Wisconsin

A 15-year-old student accused in Monday's deadly shooting at the Abundant Life Christian School in Madison, Wisconsin appears to have shown interest in online content venerating neo-Nazi violence and school shooters, according to information provided to law enforcement.

Natalie Rupnow, who went by Samantha, killed a teacher and another student, according to officials. She also injured six others, leaving two in critical condition.

She was dead of an apparent self-inflicted gunshot wound when police arrived on the scene at about 11 a.m. on Monday.

Rupnow had attended the school along with some 390 students in grades Kindergarten through 12, police said.

Apparent interest in neo-Nazism, mass shootings on social media, authorities said

In the aftermath of the shooting, police are beginning to piece together what may have led the 15-year-old to carry out the brazen attack.

Several online accounts associated with Rupnow, including Tumblr and X accounts, are being examined by police, ABC News has learned. Several mentions of shooters and violence can be seen on these accounts.

The portrait that is beginning to emerge from these social media accounts of a young person showing interest in neo-Nazi ideology and neo-Nazi violence, as well as demonstrating interest and engagement in online forums venerating mass shooters, according to information provided to law enforcement. Authorities will now review Rupnow's online footprint in an effort to glean what ideology or blend of ideologies may have motivated her to open fire, officials said.

On Tumblr, several posts show various images of guns and pictures relating to shootings -- including the account's profile picture, which is a screenshot of a security camera from a shooting, authorities said.

A picture of the Parkland high school shooter, Nikolas Cruz, can also be seen among the pictures alleged to have been posted by Rupnow.

Other posts relating to school shootings include mentions of the Columbine High School shooting and the 2007 school shooting in Jokela, Finland.

In November 2023, a GIF of a gun was posted on the Tumblr account, with text reading, "Happy birthday to me!!!"

In a post on X, the account believed to be used by Rupnow shared a video from the 2015 school stabbing in Trollhattan, Sweden, where the suspect killed a teacher, seemingly targeting people with immigrant backgrounds, according to The New York Times' reporting at the time.

Another post, dated from Dec. 13, is a video of a person taking their own life at a shooting range.

The most recent two posts to the X account were both shared on the day of the shooting at 11:45 a.m. ET and 11:50 a.m. ET, respectively. The first one was a picture of a person holding up three fingers, resembling the "OK sign" which is also known to be used as a "white power" sign. The intention of the image was not clear.

According to the Anti-Defamation League, the "OK" hand symbol is a gesture displayed by shooters in the past.

The second post on X allegedly shared by Rupnow was a Google Drive link with no explanation. ABC News has not been able to verify the contents of the link, but it was shared as a reply on the first post five minutes after the picture was posted.

A motive in the Abundant Life Christian School shooting is not clear, officials said, and it is not apparent if any of the victims were specifically targeted.

However, Madison police are aware of a document online that relates to the incident, and they are looking into it to learn more, according to Madison Police Chief Shon Barnes.

“A document about this shooting is circulating at this time on social media, but we have not verified its authenticity,” Barnes said.

Barnes also said police were "looking into her online activity" and asked "anyone who knew [Rupnow] or who may have insights into her feelings" leading up to the shooting to contact the Madison Area Crime Stoppers.

The family is cooperating, according to police

The teen shooter used a handgun, police said. Authorities are investigating the origin of the firearm, according to Barnes.

They are also speaking with her father and "trying to determine what he knew or may have not known about what happened today," Barnes said.

"But again, he lost someone as well," Barnes added.

The family is cooperating, Barnes said, adding that police are not currently looking to extend charges in connection with the deadly shooting.

"The parents are fully cooperating, we have no reason to believe that they have committed a crime at this time," Barnes said.

Police activity on the north side in Madison was confirmed as being related to the incident on Monday afternoon. Later in the evening, officials said it was the home of the shooter and that authorities were conducting a search.

Second-grade teacher called 911

The incident took place shortly before 11 a.m. local time on Monday.

“The shooting happened inside a classroom in a study hall of students from mixed grades,” Barnes said.

A second-grade teacher called 911 to report the shooting Monday morning, according to Barnes. The chief had previously stated that a second-grade student called 911, and clarified during a press briefing on Tuesday that the caller was actually a teacher.

Police believe that the suspect was in school when the attack began, and that there wasn't any breach.

However, detectives are investigating whether there were any potential warning signs, Barnes said.

The school does not have metal detectors or a school resource officer, but has other security protocols in place, according to a representative from the school.

There are cameras inside the building, police confirmed.

The school representative also confirmed that the faculty and students had been trained in lockdown procedures, which were implemented during the active shooter incident on Monday.

As of Monday evening, two of the six injured were released from SSM Health St. Mary’s Hospital.

Two others are reported in stable condition, while two are in critical condition with life-threatening injuries, officials said.

The identities of the victims have not yet been made public.