California Code, Penal Code - PEN § 902

The names of persons drawn for grand jurors shall be drawn from the grand jury box by withdrawing either the pieces of paper placed therein pursuant to subdivision (a) of Section 900 or the markers placed therein pursuant to subdivision (b) of Section 900. If, at the end of the fiscal year of the county, there are the names of persons in the grand jury box who have not been drawn during the fiscal year to serve and have not served as grand jurors, the names of such persons may be placed on the list of grand jurors drawn for the succeeding fiscal year.