The Madison school shooter has been identified as 15-year-old Natalie Rupnow

The gunman who opened fire at Abundant Life Christian School in Madison was identified as Natalie Rupnow, a 15-year-old student named Samantha, police said.

Three people died in the shooting, including Rupnow, who died of an apparent self-inflicted gunshot wound while being transported to a local hospital. A teacher and a teenage student were pronounced dead at the scene.

Six other students and a teacher were injured in the shooting, which occurred in a co-ed classroom.

Two students remain in critical condition with life-threatening injuries. A teacher and three students were treated for non-life-threatening injuries, two of whom have already been released from the hospital.

Madison Police Chief Sean Barnes said the shooting was reported at 10:57 a.m. by a second-grader who called 911. Police arrived within minutes and the first officer was on scene at 11am

“Officers boldly entered the building as soon as they arrived,” Barnes said. At 11:05 a.m., officers located the shooter and seized a weapon.

Investigators are still working to determine a motive. Police interviewed family members and searched Rupnow’s home in Madison.

The school remains an active crime scene under police surveillance. Authorities have asked people not to hold local vigils at this time.