Some incidents of violence inside the Capitol and its office buildings:

— 1835: President Andrew Jackson barely escaped assassination outside the Capitol Rotunda.

— 1915: A Harvard professor disturbed by U.S. policy toward Germany destroyed two Senate rooms with a bomb.

— 1954: Four Puerto Rican nationalists fired from the visitors' gallery in the House chamber, wounding five lawmakers, one seriously.

— 1971: An apparent Vietnam War protester in 1971 set off a bomb in a Senate restroom.

— 1983: A late-night bomb, which may have been set as a protest to U.S. military action in Grenada and Lebanon, exploded just outside the Senate chamber. No one was injured.

— 1998: Two Capitol Police officers were shot to death when a man with a history of mental illness opened fire in the Capitol. The man was wounded and captured.

(Source: Associated Press)