Secret Service agent found dead, apparent suicide-source WASHINGTON (Reuters) - A Secret Service agent assigned to President Barack Obama's protective detail was found dead on Saturday in an apparent suicide, a law enforcement source said on Thursday. Special agent Rafael Prieto was under investigation for having an unreported romantic relationship with a foreign national, the source said. The agent's death is being investigated by the District of Columbia police, said Max Milien, a spokesman for the Secret Service. "Rafael Prieto has a distinguished 20-year career with the Secret Service that was marked by accomplishment, dedication, friendships and the Secret Service is mourning a valued colleague," said Milien. Prieto was not under investigation for compromising sensitive or classified information, but because he was involved in an administrative proceeding to see if he was in violation of Secret Service rules, the source said. Gwendolyn Crump, a spokeswoman for the D.C. Metropolitan Police Department, would not provide details about an ongoing investigation. Reporting By Mark Felsenthal; Editing by Eric Walsh