CAIRO, Egypt - Images of an American hostage being decapitated surfaced Saturday on an Internet site known for carrying the statements of Islamic militants. The gruesome videotape appeared three days after U.S. authorities announced the search for the body of Paul M. Johnson Jr. had been called off. Still photographs of Johnson's beheading had been posted June 19 on some of the same militant Islamic forums that on Saturday provided links to the newly released video footage. Johnson, a 49-year-old engineer for U.S. defense contractor Lockheed Martin, was kidnapped June 12. The video, which ran almost two minutes and included...