A female worker brought a Halloween costume and a plastic gun into a congressional office building on Thursday, prompting an extraordinary shutdown of the House of Representatives, police told local television. The woman walked away from the security checkpoint before an officer was able to stop her, Chief Terrance Gainer told WRC-TV. He said there was no danger. The Cannon Office Building was shut down more than an hour, as police searched for two suspects — a man and a woman. Officials had said the man ran after security checkpoints detected a gun in his bag. The incident prompted the...