March 23 — The suspect in the previous day's mass shooting at a King Soopers supermarket in Boulder, which resulted in the deaths of ten people, is charged with ten counts of murder.[2]
May 9 — 2021 Colorado Springs shooting: Six people are killed by a gunman in a mass shooting during a birthday party at a residence in Colorado Springs. The gunman, who committed suicide at the scene, is believed to have been a boyfriend of one of the victims.[4]