McALESTER, Oklahoma  Oklahoma carried out its 13th execution of the year, killing a man who murdered a woman in a hail of gunfire at the request of her common-law husband and a friend.Vincent Allen Johnson, a 42-year-old former oil field worker, said in a taped confession he was expecting payment of dlrs 100,000 for killing Shirley Mooneyham, 44.Before the lethal injection Tuesday night, Johnson was asked if he had anything to say. He looked at the ceiling and said: +No sir, I don't.; Authorities said Johnson, firing from guns held in each hand, shot Mooneyham six times. Her estranged common-law husband, Ted Holt, was acquitted on murder charges. The friend, John Crain, was never brought to trial.During Johnson's trial he maintained his innocence, but authorities produced three earlier confessions, including one that was on audiotape.A total of 716 people have been executed in the United States since the Supreme Court lifted a moratorium on the death penalty in 1976.