Federal agents raided the offices Tuesday of a New York City police union, the Sergeants Benevolent Association, and the Long Island home of its bombastic leader, who has clashed with city officials over his incendiary tweets and hard-line tactics. FBI spokesperson Martin Feely said agents were “carrying out a law enforcement action in connection with an ongoing investigation.” Along with the union’s Manhattan headquarters, agents also searched union president Ed Mullins’ home in Port Washington, Long Island, Feely said. Messages seeking comment were left with Mullins and the union. Mullins, who is also a police sergeant, is in the middle...