A sergeant in the US Army at the tail end of the Vietnam War, Herron was less active in the field, and more persistent with backdoor dealings. After the war, he secured a comfortable job with Interpol (through the extortion of an army general with contacts at the agency). While in Ireland, he encountered David McGrath, and immediately saw potential in the Irishman. Using another contact, he seamlessly transferred to the FBI where he was given a comfortable position in the New York office.