Steve Scalise, a Republican congressman from Louisiana and House Majority Whip was shot and wounded during a baseball practice in Alexandria, Virginia, near Washington, on June 14, 2017.
FILE - Former U.S. Rep. Gabrielle Giffords, who survived a gunshot to the head in 2011 during a mass shooting in Tucson, Arizona, sits with her husband, retired astronaut Mark Kelly, at a Senate panel hearing on gun violence, on Capitol Hill in Washington, Jan. 30, 2013.
Gabrielle Giffords, former Democrat congresswoman from Arizona, was shot in the head in 2011 in her Tuscon district during a constituency meeting. She survived the attack and has gone on to become an active voice against gun violence in the U.S.
FILE - Congressman Leo Ryan is seen at a United States Bicentennial Parade, in South San Francisco, California, July 4, 1976. (Courtesy - South San Francisco Public Library)
Leo Ryan, a Democrat congressman from California, was shot multiple times and killed in 1978 while boarding an airplane after an official visit to Guyana.
Sen. John Stennis, left, is seen with then CIA director John McCone before the start of a session of the Senate Armed Services Subcommittee, on Capitol Hill in Washington, Feb. 7, 1963.
John Stennis, a Mississippi senator, was shot twice during a mugging outside his home in Washington, D.C. in 1973.
FILE - U.S. Senator Robert Kennedy addresses students at Cape Town University, in Cape Town, South Africa, June 6, 1966.
Robert Kennedy, who was a New York Senator at the time, was fatally shot in Los Angeles in 1968 after giving a speech for his presidential campaign.
In 1954, four Puerto Rican Nationalists shot Alvin Bentley of Michigan, Kenneth Roberts of Alabama, George Fallon of Maryland, Ben Jensen of Iowa, and Clifford Davis of Tennessee on the House floor in the Capitol building as they waited for their votes to be counted. All five members survived and eventually returned to Congress.