Jack B. Johnson, Prince George's County's executive, was arrested on Nov. 12 as federal investigators served search warrants at the County Administration Building. His wife, Leslie Johnson, was also arrested. Each was charged with evidence tempering and destroying evidence. Just after 10:12 a.m. Friday, Leslie Johnson frantically phoned her husband, Jack B. Johnson, the Prince George's county executive. Two FBI agents were at the front door of their two-story brick colonial in Mitchellville. "Don't answer it," the county executive said, unaware that more agents were listening in. Johnson ordered his wife to find and destroy a $100,000 check from...