June 12, 2016, Orlando
Gunman Omar Mateen killed 50 people and injured 53 in a crowded gay nightclub in Orlando, Florida, before being shot dead by police. It is said to be the worst shooting in US history.
December 2, 2015, San Bernardino
Shooters Syed Rizwan Farook and his wife Tashfeen Malik killed 14 people and wounded 22 when they opened fire at a social services agency in San Bernardino, California.
September 16, 2013, Washington
Aaron Alexis, a former Navy reservist working as a government contractor, killed 12 people at the Washington Navy Yard. Eight people were injured. The gunman was killed by police.
July 20, 2012, Aurora
A masked gunman killed 12 people and wounded 70 when he opened fire on moviegoers at a midnight premiere of the Batman film The Dark Knight Rises in Aurora, a Denver suburb. James Eagan Holmes, a former graduate student, is sentenced to life in prison for the rampage, after being found guilty on all 165 counts of murder, attempted murder and explosives offensives.
August 5, 2012, Oak Creek
Wade Michael Page, a white supremacist, walked into a Sikh temple in Oak Creek, Wisconsin, shot six worshippers and wounded four others, including a policeman. The gunman killed himself after being shot by a police officer.
December 14, 2012, Newtown
Gunman Adam Lanza killed 20 schoolchildren aged 6 and 7, and six adults and himself at Sandy Hook Elementary School in Newtown, Connecticut. Prior to the school shooting, he also shot and killed his mother at their Newtown home.
April 3, 2009, Binghamton
Vietnamese immigrant Jiverly Voong opens fire at an immigrant services center in Binghamton, New York, killing 13 people and wounding four. He then killed himself.
November 5, 2009, Fort Hood
A gunman opened fire at Fort Hood, a US Army base in Texas, killing 13 people and wounding 32. The gunman, Army major and psychiatrist Nidal Malik Hasan, was sentenced to death for the rampage.
April 16, 2007, Blacksburg
Gunman Seung-Hui Cho slaughtered 32 people and killed himself at Virginia Tech, a university in Blacksburg, Virginia.
October 2002, Manassas
John Allen Muhammad and Lee Boyd Malvo ambushed 13 people, killing 10 of them, in a string of sniper-style shootings that terrorise the Washington area.
April 20, 1999, Littleton
Two heavily armed teenagers, Eric Harris and Dylan Klebold, went on a rampage at Columbine High School in Littleton, Colorado, shooting 12 students and a teacher dead and wounding more than 20 others before taking their own lives.