Murder of Philip Barton Key II by Daniel Sickles

On February 27, 1859, Philip Barton Key II, son of Francis Scott Key, was shot and killed in Lafayette Square across from the White House by Congressman Daniel Sickles, who accused Key of an affair with his wife. The killing prompted a widely publicized trial in which Sickles was acquitted after his lawyers successfully argued temporary insanity, one of the first uses of that defense in U.S. courts. The incident heightened public attention on private scandals involving prominent Washington figures and occurred immediately north of the Executive Mansion.