Britain’s most powerful counterterrorism officer resigned on Thursday, a day after being photographed carrying a document that outlined details of a major antiterrorism operation in northwest England and was clearly marked “Secret.”
The officer, Assistant Commissioner Bob Quick of the Metropolitan Police Department, said: “I deeply regret the disruption caused to colleagues undertaking the operation.” The airing of the document, visible to waiting reporters and photographers as Mr. Quick walked to Downing Street for a security briefing, provoked a hasty flurry of arrests and raids on properties by hundreds of antiterrorism officers around Manchester, Liverpool and Lancashire late on Wednesday.