The FBI has given lie-detector tests to hundreds of employees with access to sensitive information as part of a broad internal security reform effort, Director Robert Mueller told reporters Wednesday. The agency administered polygraph exams to 700 employees after authorities arrested veteran agent Robert Hanssen in February 2001 for selling secrets to Russia for nearly two decades. Seven of the 700 employees flunked the polygraph, but failure is not an automatic indicator of wrongdoing, Mueller said. The agency has plans to periodically administer tests to additional employees. Employees at other federal law enforcement agencies, including the CIA and the Secret...