Since the late 1990s, Colorado has been the site of multiple major mass shootings, including the infamous Columbine High School massacre in 1999 which made international news, where Eric Harris and Dylan Klebold killed 12 students and one teacher, before committing suicide.The incident has since spawned many copycat incidents. On July 20, 2012, a gunman killed 12 people in a movie theater in Aurora. The state responded with tighter restrictions on firearms, including introducing a limit on magazine capacity. On March 22, 2021, a gunman killed 10 people, including a police officer, in a King Soopers supermarket in Boulder.