From the New York Daily News, massacres by gunmen in the United States since 1990:
December 2012: Newtown, Conn.: A lone gunman shot to death 28 people, including 20 children, at an elementary school.
December 2012: Portland, Ore.: A masked gunman opens fire in a crowded mall on Tuesday, killing two and seriously injuring a third before turning the gun on himself. Cops say killer’s assault weapon jammed, preventing further carnage.
August 2012: Oak Creek, Wis.: A white supremacist shoots six people and a responding policeman at a Sikh temple before shooting himself in the head .
July 2012: Aurora, Colo.: Lone gunman kills 12 and injures 58 at a screening of “The Dark Knight.”
April 2012: Oakland, Calif.: A former student at a Christian college fatally shoots seven people and injures three.
August 2011: Copley Township, Ohio: A man in a family dispute uses his handgun to shoot and kill his girlfriend and six others.
March 2009: Geneva, Ala.: Eleven victims, ages 18 months to 74 years old, are killed by a lone gunman in a violent family feud.
December 2007: Omaha, Neb.: A 19-year-old man shoots nine people at a department store before cops kill him.
April 2007: Blacksburg, Va.: A student at Virginia Tech kills 32 classmates and wounds 25 before committing suicide.
March 2005: Red Lake, Minn.: A 16-year-old boy kills 11 people, including his grandfather and his grandfather’s girlfriend, in a shooting spree.
December 2004: Columbus, Ohio: A deranged fan shoots a Pantera guitarist at a concert as he performs onstage, then fires at fans, killing four people.
Oct. 2002: Wash., D.C.: Two deranged snipers go on a spree, killing 10 people around D.C. and Virginia.
April 1999: Columbine, Colo.: Two senior students invade their school, killing 12 students and one teacher and injuring 21, before committing suicide.
October 1999: Killeen, Texas: An unemployed man drives a truck through a packed cafeteria and fatally shoots 23 people and injures 20 before killing himself.
June 1990: Jacksonville, Fla.: A man angry over a repossessed car storms into the agency and over two days shoots 11 of its 86 employees before killing himself.