WASHINGTON (AP) A middle-aged accountant with a history of mental illness fired several shots outside the White House Wednesday and then was shot by the Secret Service as he waved his handgun menacingly, authorities said. The tense, noontime standoff sent tourists running for cover. The drama unfolded just outside the fence at the edge of the South Lawn, 200 yards from the building where President Bush was inside exercising. The man, wounded in the knee and hospitalized under guard, was identified by law enforcement sources as Robert W. Pickett, 47, from Evansville, Ind. He had been fired by the Internal Revenue Service in the mid 1980s, and neighbors said he kept to himself, resented the IRS and was obsessed with West Point, where he had dropped out after a semester in 1972. Pickett had acknowledged in court records suffering from mental illness and trying to commit suicide.