A new FBI report shows a sharp increase in "active shooter" incidents in the past six years.
The report, commissioned earlier this year, defines an active shooter as an individual actively engaged in killing or attempting to kill people in a populated area.
The FBI did not include shootings involving gangs or domestic disputes - which are more common and kill the majority of the more than 10,000 Americans who die by gun homicide every year in the U.S. - in the 160 incidents they studied. Between 2000 and 2006, there was average of 6.4 active shooter events each year.
That number jumped to 16.4 between 2007 and 2013.
A total of 486 people were killed in the 160 shootings, 120 between 2000 and 2006, and 366 in the previous seven years. The deadliest year by far was 2012, with 208 fatalities from this kind of shooting.
Among those who fit into this category are Adam Lanza, who killed 27 people at Sandy Hook Elementary School in Newton, Conn., on Dec. 14, 2012; James Holmes, who killed 12 people inside a movie theater in Aurora, Colo., on July 20, 2012; and Aaron Alexis, who killed 12 people at the Washington Navy Yard in Washington, D.C., on September 16, 2013.
Forty percent of the shooters ultimately committed suicide and in 23 percent of the incidents, the shooter committed suicide before police arrived. In 13 percent of the shootings unarmed citizens restrained the shooter and just over three percent of the shootings were stopped after armed civilians exchanged gunfire with the shooter.
Only six of the incidents involved a female shooter, and the report states that five of them are still at-large. In 10 percent of the shootings, perpetrators targeted current, former or estranged wives or girlfriends.
Forty-five percent of the 160 incidents occurred in commercial locations and 24 percent at educational institutions. Just over 10 percent of the incidents occurred on government property.