A gunman walked into an immigration services center in downtown Binghamton, N.Y. on Friday, killing an unknown number of people, wounding at least six, and taking as many as 41 hostage. Here is a glance at some of the worst U.S. mass shootings in recent years:
— March 29, 2009: Robert Stewart, 45, shot and killed eight people at Pinelake Health and Rehab in Carthage, N.C. before a police officer shot him and ended the rampage.
— March 29, 2009: Devan Kalathat, 42, shot and killed his two children and three other relatives, then killed himself in an upscale neighborhood of Santa Clara, Calif. Kalathat's wife was critically injured.
— March 10, 2009: Michael McLendon, 28, killed 10 people — including his mother, four other relatives, and the wife and child of a local sheriff's deputy — across two rural Alabama counties. He then killed himself.
— Feb. 14, 2008: Former student Steven Kazmierczak, 27, opened fire in a lecture hall at Northern Illinois University in DeKalb, fatally shooting five students and wounding 18 others before committing suicide.
— Dec. 5, 2007: Robert A. Hawkins, 19, opened fire with a rifle at a Von Maur store in an Omaha, Neb., mall, killing eight people before taking his own life. Five more people were wounded, two critically.
— April 16, 2007: Seung-Hui Cho, 23, fatally shot 32 people in a dorm and a classroom at Virginia Tech in Blacksburg, then killed himself in the deadliest mass shooting in modern U.S. history.
— Oct. 2, 2006: Charles Carl Roberts IV, 32, shot to death five girls at West Nickel Mines Amish School in Pennsylvania, then killed himself.
— March 21, 2005: Student Jeffrey Weise, 16, killed nine people, including his grandfather and his grandfather's companion at home. Also included were five fellow students, a teacher and a security guard at Red Lake High School in Red Lake, Minn. He then killed himself. Seven students were wounded.
— March 12, 2005: Terry Ratzmann, 44, gunned down members of his congregation as they worshipped at the Brookfield Sheraton in Brookfield, Wisconsin, slaying seven and wounding four before killing himself.
— March 5, 2001: Charles "Andy" Williams, 15, killed two fellow students and wounded 13 others at Santana High School in Santee, Calif.
— Nov. 2, 1999: Copier repairman Byran Uyesugi, 40, fatally shoots seven people at Xerox Corp. in Honolulu. He is convicted and sentenced to life in prison.
— July 29, 1999: Former day trader Mark Barton, 44, killed nine people in shootings at two Atlanta brokerage offices, then killed himself.
— April 20, 1999: Students Eric Harris, 18, and Dylan Klebold, 17, opened fire at Columbine High School in Littleton, Colo., killing 12 classmates and a teacher and wounding 26 others before killing themselves in the school's library.
— May 21, 1998: Two teenagers were killed and more than 20 people hurt when Kip Kinkel, 17, opened fire at a high school in Springfield, Ore., after killing his parents.
— March 24, 1998: Andrew Golden, 11, and Mitchell Johnson, 13, killed four girls and a teacher at a Jonesboro, Ark., middle school. Ten others were wounded in the shooting.
— Oct. 16, 1991: A deadly shooting rampage took place in Killeen, Texas, as George Hennard opened fire at a Luby's Cafeteria, killing 23 people before taking his own life. 20 others were wounded in the attack.
— June 18, 1990: James Edward Pough shoots people at random in a General Motors Acceptance Corp. office in Jacksonville, Fla., killing 10 and wounding four, before killing himself.
— July 12, 1976: Edward Charles Allaway, a custodian in the library of California State University, Fullerton, fatally shot seven fellow employees and wounded two others.
— Aug. 20, 1986: Pat Sherrill, 44, a postal worker who was about to be fired, shoots 14 people at a post office in Edmond, Okla. He then kills himself.
— July 18, 1984: James Oliver Huberty, an out-of-work security guard, kills 21 people in a McDonald's restaurant in San Ysidro, Calif. A police sharpshooter kills Huberty.
— May 4, 1970: Four Kent State University students were killed by Ohio National Guard troops during a campus protest of the invasion of Cambodia. Nine people were wounded.
— Aug. 1, 1966: Charles Whitman opened fire from the clock tower at the University of Texas at Austin, killing 16 people and wounding 31.