Some fatal shootings at U.S. workplaces:
— Aug. 3, 2010: Warehouse driver Omar Thornton shot and killed eight people before apparently committing suicide at a Manchester, Conn., beer distributorship.
Feb. 12, 2010: Three biology professors were shot and killed and three other employees injured at the University of Alabama's Huntsville campus. Amy Bishop, a 42-year-old instructor and researcher at the school, is charged with murder in the shooting deaths.
— Nov. 5, 2009: At Fort Hood, Texas, 13 people were fatally shot and 32 were injured. Army psychiatrist Maj. Nidal Malik Hasan, 39, is charged with 13 counts of premeditated murder.
— June 25, 2008: Wesley N. Higdon, 25, killed five workers, then himself, at Atlantis Plastics in Henderson, Ky. A sixth shooting victim survived.
— March 18, 2008: Lee Isaac Bedwell Leeds, 31, shot and killed four men at a junk yard in Santa Maria, Calif.
— March 12, 2008: Robert Lanham killed two people in the Regions Bank of McComb, Miss., where his ex-wife worked, then forced the woman to flee with him before killing her and committing suicide.
— Jan. 30, 2006: Former postal worker Jennifer San Marco, 44, shot and killed six postal employees, then himself, in Goleta, Calif.
— July 2, 2004: Elijah Brown, 21, killed four co-workers and wounded three others at ConAgra Foods meatpacking plant in Kansas City, Kan., before committing suicide.
— August 27, 2003: Recently fired Salvador Tapia, 36, killed six former co-workers at an auto parts warehouse in Chicago, then was shot dead by police.
— July 8, 2003: Doug Williams, 48, shot and killed six workers and wounded eight others before killing himself at a Lockheed Martin aircraft parts plant in Meridian, Miss.
—Feb. 25, 2003: Emanuel Burl Patterson, 23, shot and killed four fellow jobseekers and wounded a fifth at a temporary employment service in Huntsville, Ala.
— Feb. 5, 2001: Factory worker William D. Baker, 66, killed four co-workers, then himself, at the Navistar International factory in suburban Chicago, Ill.
— Dec. 26, 2000: Software tester Michael McDermott, 43, shot and killed seven people at a Wakefield, Mass., Internet consulting company, Edgewater Technology Inc. He was convicted, sentenced to life without parole.
— March 20, 2000: Fired employee Robert Harris, 28, fatally shot five people and wounded another at a Dallas-area car wash. He was convicted, sentenced to death.
— Dec. 30, 1999: Housekeeper Silvio Izquierdo-Leyva, 36, fatally shot five co-workers at Tampa, Fla.'s Radisson Bay Harbor hotel. He pleaded guilty, was sentenced to life in prison.
— Nov. 2, 1999: Copier repairman Byran Uyesugi, 40, fatally shot seven people at Xerox Corp. in Honolulu. He was convicted, sentenced to life in prison.
— Aug. 5, 1999: Truck driver Alan E. Miller, 35, fatally shot two co-workers at Pelham, Ala., office, then killed a former co-worker. He was convicted, sentenced to death.
— July 29, 1999: Former day trader Mark Barton, 44, killed nine people at two Atlanta brokerage offices before he committed suicide.
— March 6, 1998: Former Connecticut Lottery Corp. accountant Matthew Beck, 35, fatally shot four lottery executives, then himself.
— Dec. 18, 1997: Fired employee Arturo R. Torres, 43, killed four former co-workers at maintenance yard in Orange, Calif., and was shot to death by police.
— Sept. 15, 1997: Fired assembly line worker Arthur H. Wise, 43, shot and killed four at Aiken, S.C., parts plant. He was convicted, sentenced to death.
— April 24, 1996: Firefighter Kenneth Tornes killed four superiors at Jackson, Miss. firehouse. He died on death row.
— April 3, 1995: Former employee James Simpson, 28, shot and killed five people at refinery inspection station in Corpus Christi, Texas, then killed himself.
— July 19, 1995: City electrician Willie Woods shot and killed four supervisors at C. Erwin Piper Technical Center in Los Angeles. He was sentenced to life in prison.
— July 1, 1993: Gian Luigi Ferri, 55, a mentally disturbed man with a grudge against lawyers, killed eight people and himself in a San Francisco law office.
— June 18, 1990: James E. Pough, 42, killed 10 people and wounded four others before killing himself at a General Motors Acceptance Corp. office in Jacksonville, Fla.
— Sept. 14, 1989: Joseph T. Wesbecker, 47, on disability for mental illness, killed eight people and wounded 12 others at a printing plant in Louisville, Ky., before killing himself.
— Feb. 16, 1988: Richard W. Farley, 40, killed seven people with a shotgun at ESL Corp. in Sunnyvale, Calif., before surrendering. He was sentenced to death.
— Aug. 20, 1986: Pat Sherrill, 44, a postal worker who authorities say was about to be fired, killed 14 people at a post office in Edmond, Okla., then fatally wounded himself.
Compiled by AP News Researcher Julie Reed Bell