An 18-year-old student who opened fire at a Colorado high school on Friday (December 13) was reportedly seeking revenge against his teacher because of a disagreement.
The shooter, identified as 18-year-old Karl Halverson Pierson, was enrolled at Arapahoe High School. He shot a 15-year-old girl before taking his own life. The conditions of the wounded girl remains critical after surgery.
According to Reuters, the targeted teacher immediately fled the school and was not injured. The shooter was later found inside a classroom, dead of a self-inflicted gunshot wound. Authorities found two Molotov cocktail-like incendiary devices in the school. One was detonated by the suspect and the other one was rendered harmless by authorities.
The incident came a day before the first anniversary of the mass shooting at Sandy Hook Elementary School in Connecticut, in which a gunman killed 20 children and six adults before killing himself.