PRELIMINARY INVESTIGATION:

     the purpose of preliminary investigation is to determine whether (a) a crime has been committed; and (b) whether there is a probable cause to believe that the accused is guilty thereof. x x x In a preliminary investigation, the public prosecutor merely determines whether there is probable cause or sufficient ground to engender a well-founded belief that a crime has been committed, and that the respondent is probably guilty thereof and should be held for trial. (George Miller vs. Secretary Hernando B. Perez, G.R. No. 165412, May 30, 3011, VILLARAMA, JR., J.).