Shootings at hospitals are far from rare.
Still, the shooting on Monday at Mercy Hospital in Chicago that claimed the lives of four people, including the shooter, is among the worst in the U.S. in more than two decades. On June 20, 1994, former airman Dean A. Mellberg fired on a military hospital at Fairchild Air Force Base in Spokane, Washington, killing four people and wounding 23 others before military police shot him to death. Two of those killed in the five-minute rampage were therapists who had recommended Mellberg's discharge.
Here is a look at other fatal hospital shootings in recent years:
— Aug. 8, 2018: A man who said he wanted to end his ailing wife's suffering shot her to death in her bed at Westchester Medical Center in Valhalla, New York, then took his own life.
— Dec. 20, 2017: A gunman opened fire in the psychiatric services emergency room at the University of Cincinnati Medical Center, wounding an unarmed security officer before shooting himself to death.
— Sept. 12, 2017: A man fatally shot his 70-year-old mother who was a patient at Dartmouth-Hitchcock's intensive care unit in Lebanon, New Hampshire.
— June 30, 2017: A doctor who had been forced to resign from Bronx Lebanon Hospital in New York City two years earlier amid a sexual harassment claim opened fire inside the hospital with an assault rifle, killing Dr. Tracy Sin-Yee Tam and wounding six others before killing himself.
— July 17, 2016: A man entered Parrish Medical Center in Titusville, Florida, and fatally shot a 92-year-old patient and a hospital-affiliated attendant in an apparently random attack.
— Jan. 20, 2015: Dr. Michael J. Davidson, director of endovascular cardiac surgery at Brigham and Women's Hospital in Boston, was shot and killed outside an examination room by a man who later died of a self-inflicted gunshot.
— Dec. 17, 2013: A gunman who blamed his doctor for a botched vasectomy fatally shot another doctor, critically injured two others and killed himself at Renown Regional Medical Center in Reno, Nevada.
— Oct. 16, 2012: A family dispute led an 85-year-old man to fatally shoot his wife's 59-year-old nephew, while the nephew was visiting his aunt at University Hospital in Augusta, Georgia.
— Aug. 4, 2012: John Wise, 68, fatally shot his wife of 45 years as she lay debilitated in a hospital bed at Akron General Medical Center in Ohio. Wise told police he was acting out of love and also intended to kill himself, but the weapon jammed.
— March 8, 2012: Nurse Michael Schaab was killed at a psychiatric hospital at the University of Pittsburgh Medical Center's Western Psychiatric Institute and Clinic campus by a gunman with schizophrenia who also shot five other employees.
— Nov. 24, 2011: A housekeeping employee fatally shot a fellow employee inside a parking garage at the University of Illinois at Chicago hospital in what police called an "apparent domestic-related shooting."
— April 19, 2010: A man who thought his surgeon had implanted a computer chip in him to track his movements during an appendectomy years earlier opened fire outside the Parkwest Medical Center in Knoxville, Tennessee, killing one hospital worker and wounding two others before killing himself.
— June 13, 2009: A woman fatally shot her estranged husband of 38 years in his hospital bed at Charleston Area Medical Center Memorial Hospital's intensive-care unit in Charleston, West Virginia. Initially found guilty of first-degree murder, Rhonda Kay Stewart later won a new trial to present a Battered Woman's Syndrome defense.
— Nov. 27, 2008: A worker returned to Central Peninsula Hospital in Soldotna, Alaska, a day after being fired, and shot one of his ex-supervisors to death. Another was critically injured before he was fatally shot by authorities.
— Sept. 29, 2005: A man arrested for drunken driving grabbed a police officer's gun, wounding the officer and an emergency room technician and shot another officer to death at St. Mary Medical Center in Middletown Township, Pennsylvania.
— May 16, 2002: A nurse was shot to death and another critically wounded after being shot outside the North Central Medical Center in McKinney, Texas, while returning from lunch. The husband of one of the women later pleaded guilty to the sniper-style crimes.
Source: AP reporting.
Compiled by News Researcher Jennifer Farrar in New York.