US school shooter carried AR-15-style rifle, 600 bullets

The 19-year-old gunman who killed a teacher and a 15-year-old girl at a St Louis high school was armed with an AR-15-style rifle and what appeared to be more than 600 rounds of ammunition, officials said.

Orlando Harris also left behind a hand-written note offering his explanation for the shooting on Monday at Central Visual and Performing Arts High School, police commissioner Michael Sack said on Tuesday.

Tenth-grader Alexzandria Bell and 61-year-old physical education teacher Jean Kuczka died and seven students were wounded before police killed Harris in an exchange of gunfire.

Sack read Harris' note in which the young man lamented that he had no friends, no family, no girlfriend and a life of isolation. In the note, Harris called it the "perfect storm for a mass shooter."

Sack said Harris had some ammo strapped to his chest, some in a bag, and other magazines were found dumped in stairwells.

"This could have been much worse," Sack said.

The attack forced students to barricade doors and huddle in classroom corners, jump from windows and run out of the building to seek safety.

 One terrorised girl said she was eye-to-eye with the shooter before his gun apparently jammed and she was able to run out. 

Sack, speaking at a news conference, urged people to come forward when someone who appears to suffer from mental illness or distress begins "speaking about purchasing firearms or causing harm to others."

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Incident breakdown

The school in south St Louis was locked, with seven security guards at the doors, St Louis Schools Superintendent Kelvin Adams said.

A security guard initially became alarmed when he saw Harris trying to get in one of the doors. He was armed with a gun and "there was no mystery about what was going to happen.

That guard alerted school officials and made sure the police were contacted.

Harris managed to get inside anyway — Sack declined to say how, saying he didn't want to "make it easy" for anyone else who wants to break into a school.

Police offered this timeline of events: A 911 call came in at 9:11 am [local time] alerting police of an active shooter.

Officers — some off-duty wearing street clothes — arrived at 9:15 am

Police located Harris at 9:23 am on the third floor of the school, where he had barricaded himself inside a classroom.

Police said in a news release that when Harris shot at officers, they shot back and broke through the door.

At 9:25 am, when Harris pointed his rifle at police, they fired several shots. He was secured by police at 9:32 am.

Police said Alexzandria was found in a hallway and died at the scene. Kuczka was found in a classroom and died at a hospital.

It was the 40th school shooting this year resulting in wounds or death, according to a tally by Education Week — the most in any year since it began tracking shootings in 2018.

The deadly attacks include the killings at Robb Elementary School in Uvalde, Texas, in May, when 19 children and two teachers died.

READ MORE: US accounted for 73 percent of global mass shootings