FBI agents violated the Fourth Amendment when they secretly recorded a suspect who was alone in an interrogation room whispering to himself, a federal judge ruled.In a written opinion Wednesday, U.S. District Judge Sara L. Ellis denied a motion by prosecutors to use Jorge Llufrio’s statements as evidence at his trial on drug charges.Llufiro had a legitimate expectation of privacy in the words he spoke to himself, Ellis wrote.And FBI agents intruded on that privacy, she wrote, when they recorded Llufrio’s words …