The prosecuting attorney (1) shall submit an indictment to the grand jury and cause the evidence in support of the indictment to be brought before them in every case when a person is held to answer a criminal charge in the court where the jury is formed;
(2) may submit an indictment in any case when the prosecuting attorney has good reason to believe a crime has been committed that is triable by the court; and
(3) shall, when required by the grand jury, prepare indictments or presentments for them and attend their sittings to advise them in relation to their duties or to examine witnesses in their presence.