A man opened fire on a church in South Texas on Sunday, killing more than 20 people and wounding others.
Here's a look at some of the nation's deadliest mass shootings since 2012:
— Oct. 1, 2017: A gunman identified by authorities as Stephen Paddock opened fire on an outdoor music festival on the Las Vegas Strip from the 32nd floor of a hotel-casino, killing 58 people and wounding more than 500. SWAT teams with explosives then stormed his room and found he had killed himself.
— June 12, 2016: Gunman Omar Mateen opened fire at an Orlando, Florida, nightclub, killing 49 people. Mateen was later killed in a shootout with police.
— Feb. 25, 2016: Cedric Ford, 38, killed three people and wounded 14 others at a lawnmower factory where he worked in the central Kansas community of Hesston. The local police chief killed him during a shootout with 200 to 300 workers still in the building, authorities said.
— Feb. 20, 2016: Jason Dalton, 45, is accused of randomly shooting and killing six people and severely wounding two others during a series of attacks over several hours in the Kalamazoo, Michigan, area. Authorities say he paused between shootings to make money as an Uber driver. He faces murder and attempted-murder charges.
— Dec. 2, 2015: Syed Rizwan Farook, 28, and Tashfeen Malik, 27, opened fire at a social services center in San Bernardino, California, killing 14 people and wounding more than 20. They fled the scene but died hours later in a shootout with police.
— Oct. 1, 2015: A shooting at Umpqua Community College in Roseburg, Oregon, left 10 people dead and seven wounded. Shooter Christopher Harper-Mercer, 26, exchanged gunfire with police, then killed himself.
— June 17, 2015: Dylann Roof, 21, shot and killed nine African-American church members during a Bible study group inside the Emanuel African Methodist Episcopal Church in Charleston, South Carolina. Police contend the attack was racially motivated. Roof has been sentenced to death in the shootings.
— May 23, 2014: A community college student, Elliot Rodger, 22, killed six people and wounded 13 in shooting and stabbing attacks in the area near the University of California, Santa Barbara, campus. Authorities said he apparently shot himself to death after a gunbattle with deputies.
— Sept. 16, 2013: Aaron Alexis, a mentally disturbed civilian contractor, shot 12 people to death at the Washington Navy Yard before he was killed in a police shootout.
— July 26, 2013: Pedro Vargas, 42, went on a shooting rampage at his Hialeah, Florida, apartment building, gunning down six people before officers fatally shot him.
— Dec. 14, 2012: In Newtown, Connecticut, an armed 20-year-old man entered Sandy Hook Elementary School and used a semi-automatic rifle to kill 26 people, including 20 first-graders and six adult school staff members. He then killed himself.
— Sept. 27, 2012: In Minnesota's deadliest workplace rampage, Andrew Engeldinger, who had just been fired, pulled a gun and fatally shot six people, including the company's founder. He also wounded two others at Accent Signage Systems in Minneapolis before taking his own life.
— Aug. 5, 2012: In Oak Creek, Wisconsin, 40-year-old gunman Wade Michael Page killed six worshippers at a Sikh Temple before killing himself.
—July 20, 2012: James Holmes, 27, fatally shot 12 people and injured 70 in an Aurora, Colorado, movie theater. He was sentenced to life in prison without parole.
— April 2, 2012: Seven people were killed and three were wounded when a 43-year-old former student opened fire at Oikos University in Oakland, California. One Goh was charged with seven counts of murder and three counts of attempted murder, but psychiatric evaluations concluded he suffered from long-term paranoid schizophrenia and was unfit to stand trial.