When he wasn't sending pornographic movies to and asking for explicit photos from a teenage girl in Polk County, a Maryland man was bragging about his job as a spokesman at the U.S. Department of Homeland Security, law enforcement officers said. The revelation - actually made to a detective posing as a 14-year-old girl - resulted in the arrest of 55-year-old Brian J. Doyle at his Silver Spring, Md., home Tuesday night, officials said. During his Internet chats, Doyle quickly revealed his name and job, and he sent his office and government-issued cell phone numbers. The information allowed detectives to quickly verify Doyle's identity, the Polk County Sheriff's Office announced Tuesday night.