In this framegrab taken from video by KCNC television news in Denver, students of Arapahoe High School in Centennial, Colorado, line up to be checked by police at a running track on December 13, 2013 after a shooting at the school. Two students were injured in the shooting incident before the suspected gunman apparently killed himself, the local sheriff said. The suspect was also a student. “That individual is .. deceased, he apparently killed himself,” Arapahoe County Sheriff Grayson Robinson told reporters. (AFP/Getty Images)