One of President Obama’s top Secret Service agents has died in an apparent suicide. Rafael Prieto, 47, was a married father who had confessed to cheating with a Mexican woman for nearly six years, a secret under investigation for allegedly violating agency rules that require disclosure of relationships with foreign nationals. A member of the Secret Service for more than two decades assigned to the agency’s most prestigious post as the President’s protective detail, Prieto was found inside a car parked in a Northwest Washington, D.C. apartment complex garage last week, dead of what authorities believe to be carbon monoxide...