Maryland state police and federal agents used a search warrant in an unrelated criminal investigation to seize the private reporting files of an award-winning former investigative journalist for The Washington Times who had exposed problems in the Homeland Security Department’s Federal Air Marshal Service. Reporter Audrey Hudson said the investigators, who included an agent for Homeland’s Coast Guard service, took her private notes and government documents that she had obtained under the Freedom of Information Act during a predawn raid of her family home on Aug. 6. The documents, some which chronicled her sources and her work at the Times...