CENTENNIAL, Colo. — A teenager who may have had a grudge against a teacher opened fire Friday with a shotgun at a suburban Denver high school, wounding a fellow student and killing himself.
Quick-thinking students alerted the targeted teacher, who quickly left the building. The scene unfolded on the eve of the Newtown massacre anniversary.
The wounded student, a 15-year-old girl, underwent surgery and was in critical condition. Authorities originally said a second student was wounded, but Arapahoe County Sheriff Grayson Robinson said Friday night that the other girl taken to a hospital was covered in blood from the other student, but wasn't injured.
Robinson identified the shooter as Karl Halverson Pierson, 18. The sheriff did not elaborate on any possible motive except to say Pierson had had a "confrontation or disagreement" with the teacher.
Pierson made no attempt to hide his weapon after entering the school from a parking lot and asking for the teacher by name, Robinson said.
Jessica Girard was in math class when she heard three shots.
"Then there was a bunch of yelling, and then I think one of the people who had been shot was yelling in the hallway 'Make it stop,' " she said.
Two suspected Molotov cocktails were also found inside the school, the sheriff said. One detonated, though no one was injured.
The school was swiftly locked down. Within 20 minutes of the first report of a gunman, officers found Pierson's body inside the school, Robinson said.
Several other Denver-area school districts went into lockdown as reports of the shooting spread. Police as far away as Fort Collins, about a two-hour drive north, stepped up school security.
Arapahoe High students were seen walking toward the school's running track with their hands in the air, and television footage showed students being patted down. Robinson said deputies wanted to make sure there were no other conspirators. Authorities later concluded that Pierson had acted alone.
Arapahoe High, where 2,100 students attend, stands just 8 miles east of Columbine High School in Littleton, where two teenage shooters killed 12 classmates and a teacher before killing themselves in 1999. It is about 17 miles from Aurora, where a gunman killed 12 inside a movie theater in 2012.
Tracy Monroe, who had step-siblings who attended Columbine, was standing outside the school on Friday looking at her phone, reading text messages from her 15-year-old daughter inside.
Monroe said she got the first text from her daughter, sophomore Jade Stanton, at 12:41 p.m. The text read, "There's sirens. It's real. I love you."
A few minutes later, Jade texted "shots were fired in our school." Monroe rushed to the school and was relieved when Jade texted that a police officer entered her classroom and she was safe.
Monroe was family friends with a teacher killed in the Columbine shooting, Dave Sanders.
"We didn't think it could happen in Colorado then, either," Monroe said.