A student at Arapahoe High School in Colorado arrived at school on Friday, carrying a rifle with which he ended his own life and put a 15-year-old girl in critical condition.

School Shooting At Arapahoe High

The shooter, 18-year-old senior Karl Pierson, is believed to have acted alone. In the aftermath of his attack on the school and his apparent suicide, authorities launched an investigation, reported the Denver Post. Law enforcement is searching Pierson’s car, his home in Highlands Ranch and his father’s residence in Denver.

It’s been suggested that Pierson was motivated by a confrontation with the teacher who coached his debate team. The student reportedly shouted out his name as he took to the high schools halls with the rifle, according to Arapahoe County Sheriff Grayson Robinson.

Karl Pierson Targeted Teacher

The school employee who Pierson was believed to be after heard Pierson calling his name, and made an attempt to lure him outside the school and away from the students, according to Robinson, who called the move “the most important tactical decision that could be made.”

“He took himself away from the school in an effort to try to encourage the student to move with him,” Robinson continued.

Despite the unidentified teacher’s efforts, Pierson remained in the school. Before long, the school’s resource officer came upon the 15-year-old girl in the school’s athletic hall. Within minutes, she was taken to Littleton Adventist Hospital, where she had surgery for her wounds.

Arapahoe High School sits eight miles east of Columbine High School, where 12 students and a teacher were killed in 1999 by two armed students. The school is also just 15 miles away for the Aurora movie theater where a gunman killed 12 and injured 70 in 2012.

– Chelsea Regan

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