The inspector general for the Department of Homeland Security said Tuesday that he is investigating the leak of classified information from an undercover operation in which investigators were able to slip through airport security with weapons and phony bombs more than 95 percent of the time. “We have started an investigation to determine where the leak was,” Inspector General John Roth told the Senate Homeland Security Committee. The information received widespread attention in the news media and on Capitol Hill. Roth told the panel that he had briefed top officials about his findings without the information leaking to the public....