A gunman killed 10 people, including a police officer, at a King Soopers grocery store in Boulder on Monday afternoon, March 22, 2021, plunging the university town into what local authorities called “a tragedy and a nightmare.” Sadly, this isn’t the first mass shooting in Colorado.

Chuck E. Cheese, 1993, 4 dead 

On Dec. 14, 19-year-old gunman and former employee Nathan Dunlap opened fire on the staff of an Aurora Chuck E. Cheese, killing four and injuring one employee. 

Columbine High School, 1999, 15 dead 

Two armed teens went on a shooting spree April 20, killing 12 students and one teacher, and wounding more than 20 others. After the attack, gunmen Eric Harris, 18, and Dylan Klebold, 17, killed themselves. At the time, this was the largest school shooting in U.S history. 

Platte Canyon High School, 2006, 2 dead 

On Sept. 27, armed 53-year-old Duane Roger Morrison entered Platte Canyon High School taking six young girls hostage and sexually assaulted them. Following a three-hour standoff with police, Morrison killed one of the girls before turning the gun on himself. 

Youth With a Mission Center and New Life Church, 2007, 5 dead

In the morning on Dec. 9, 24-year-old Matthew John Murray opened fire on the Youth With a Mission Center in Arvada, Colorado. He killed two, and injured two before escaping. Later that day, he made a similar attack on New Life Church in Colorado Springs, killing two and wounding three before shooting himself. 

Aurora Movie Theater, 2012, 12 dead 

One armed gunman, later identified as 25-year-old James Holmes, opened fire at a midnight showing of Batman: the Dark Knight Rises, killing 12 and leaving 70 wounded. 

Arapahoe High School, 2013, 2 dead

Student and gunman Karl Pierson, 18, made an armed attack on Dec. 13 that killed one 17-year-old girl. Pierson took his own life on the scene.  

Planned Parenthood, 2015, 3 dead 

An armed anti-abortion radical enter a Planned Parenthood facility in Colorado Springs on Nov. 27, killing three including one police officer. Following a standoff that lasted nearly five hours and resulted nine others injured, the shooter was identified as Robert Lewis Dear Jr, 57. 

Walmart, 2017, 3 dead 

On Nov. 1, 47-year-old Scott Ostrem opened fire in a Thornton Walmart, killing three shoppers. Ostrem escaped the scene and was later found and arrested in Westminster.

STEM school, 2019, 1 dead 

An 18-year-old student, Devon Erickson, opened fire in the Highlands Ranch school, killing 1 teen and leaving 8 others injured. The 18-year-old victim and two other students charged Erickson, an effort that disarmed the shooter but resulted in the student being fatally shot to the chest. 

King Soopers, 2021, 10 dead 

March 22, a gunman attacked a Boulder King Soopers grocery store. The suspect has not yet been identified by officials. Police confirmed that at least 10 were killed in the store including one police officer.