Girl, 15, behind deadly school shooting which killed student and teacher, officials say

A 15-year-old girl who is responsible for a school shooting that killed a teenage student and a teacher in Wisconsin had planned the attack well in advance, according to law officials.

Two students are fighting for life in a critical condition, while a teacher and three others have been treated for non-life-threatening injuries at various hospitals following the shooting at Abundant Life Christian School about 10.57am local time.

A law enforcement source has revealed to CNN that the shooter had been dealing with problems and expressed some of those in writings, which police are now reviewing.

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Madison Police Chief Shon Barnes confirmed the parents of the shooter were cooperating with authorities.

They are being interviewed by detectives.

Law enforcement officials told CNN the girl was a student at the private school and believed she was at school before the shooting.

It is believed the shooter died of a self-inflicted gunshot, another source told CNN.

While police have not publicly released any information about the shooter, they confirmed that they were found dead when officers arrived at the scene.

Police earlier believed five people had died, but have since confirmed three were killed.

Barnes said the shooting was "confined to one space" and happened in "a learning part of the school."

It's not clear if the shooting unfolded inside a classroom or in the hallway.

A spokesperson for SSM Health St. Mary's Hospital confirmed to AP they had received patients from the shooting, but would not disclose further details.

Barnes said police officers who responded did not fire their weapons, but confirmed a handgun was found at the school.

He did not elaborate on the weapon found but said the shooting was confined to one space.

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Shooting shocks community

Students have been reunited with their families after parents were directed to a medical clinic building about a kilometre from the school to pick up their children.

Some left the clinic holding their young children against their chests, others squeezing kids' hands or shoulders as they walked side by side, the Associated Press reported.

Abundant Life Christian School elementary and school relations director Barbara Wiers said the shooting had "rocked" the school community.

"We know it affects not just our school community, but Madison and the greater area and all schools," Wiers said.

"And so our hope is that there will be some good that comes out of this as we can learn and grow and continue to support schools."

Wiers revealed the school did not have metal detectors but said "a number of security protocols in place".

She said the school had completed training with the Madison Police Department earlier this year about what to do in an active shooter situation.

"So I think everything was very fresh for our faculty," Wiers said.

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Barnes described the shooting as a "sad" day for the community.

"I'm feeling a little dismayed now, so close to Christmas," Barnes said.

"Every child, every person in that building is a victim, and will be a victim forever. These types of trauma don't just go away.

"My heart is heavy for Madison and we have to come together as a community and find out what happened here and make sure it doesn't happen in any other place that should be a refuge for students in our community.

"These types of trauma don't just go away, we need to figure out and piece together what actually happened."

The Abundant Life Christian School has since posted on Facebook, asking for community members to send prayers.

"Prayers Requested! Today, we had an active shooter incident at ALCS. We are in the midst of following up," the post said.

"We will share information as we are able. Please pray for our Challenger Family."

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Police had blocked off roads around the school following the shooting.

Barnes said the attack took place about 4.8km away from a police training centre.

He said officers that arrived at the shooting "got to practice in real time".

"They left the training centre and began doing in real-time what they had actually practiced," he said.

Agents from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives have responded to the scene to assist local law enforcement.

"We are praying for the kids, educators, and entire Abundant Life school community as we await more information and are grateful for the first responders who are working quickly to respond," Wisconsin Governor Tony Evers said in a statement.

Abundant Life Christian School is nondenominational and has about 420 students, from kindergarten through high school, according to its website.

There have been 322 school shootings this year in the US, according to the K-12 School Shooting Database website.

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