So far this year, the United States has seen at least six mass shootings, including Thursday night's violence at an Indianapolis FedEx Facility.
NBC News defines a mass shooting as a single incident involving three or more people who have been shot — either injured or killed — in a public place, excluding the shooter. Isolated fights, including gang and drug violence, domestic disputes, and robberies turned violent are not considered mass shooting incidents.
A look at 2021's mass shootings:
April 15: Indianapolis
Eight people were killed after a gunman opened fire at a FedEx facility in Indianapolis. Four others who were shot and another who was injured were taken to hospitals. Officials said the gunman killed himself at the scene. The suspect has been identified as 19-year-old Brandon Scott Hole. His motive remains unclear.
April 8: Bryan, Texas
One person was killed, and five others were wounded during a workplace shooting at a manufacturing facility, Kent Moore Cabinet, in Bryan, Texas. The suspected gunman, Larry Bollin, 27, an employee, was arrested in a nearby county by state troopers, and one trooper was also shot and wounded at that time. Bollin has been charged with murder and five counts of aggravated assault, but his motive remains unknown.
March 22: Boulder, Colo.
In late March, a gunman killed 10 people, including a police officer, after walking into a Boulder, Colo., grocery store and randomly shooting at shoppers. Police say suspect Ahmad Al Aliwi Alissa, 21, bought a high-powered weapon less than a week before the shooting. He has been charged with 10 counts of first-degree murder.
March 16: Acworth and Atlanta, Ga.
Eight people, including six women of Asian descent, were killed at three Atlanta-area spas. The attacks began near Acworth in Cherokee County, where four people died. Less than an hour later, four women were killed in two shootings in Atlanta. One person was injured.
The slayings raised alarm among the Asian American community, which has faced an increasing number of attacks during the coronavirus pandemic.
February 9: Buffalo, Minn.
In early February, one person was killed and four were injured in a shooting at the Allina Health Clinic in Buffalo, Minn. Gregory Paul Ulrich, 67, was charged with second-degree murder, four counts of first-degree attempted murder, possession of an explosive device, and carrying a firearm without a license.
In 2018, Ulrich was accused of threatening to attack four Allina Health medical facilities, including the clinic in Buffalo, according to police.
January 9: Chicago and Evanston, Ill.
Five people were killed, including a 15-year-old, and two injured in a "murderous rampage" in Chicago and nearby Evanston. The suspect, Jason Nightengale, 32, was killed after a shoot-out with police.