Section 190.15. Grand jury; duration of term and discharge

1.    A  term  of  a  superior  court  for which a grand jury has been
  impaneled remains in existence at least until and including the  opening
  date  of  the  next  term  of such court for which a grand jury has been
  designated.  Upon such date, or within five days preceding it, the court
  may, upon declaration of both the grand jury and the  district  attorney
  that such grand jury has not yet completed or will be unable to complete
  certain  business  before it, extend the term of court and the existence
  of such grand jury to a specified  future  date,  and  may  subsequently
  order further extensions for such purpose.
    2.    At  any  time  when  a  grand  jury  is  in  recess and no other
  appropriate grand jury is in existence in the  county,  the  court  may,
  upon  application  of  the district attorney or of a defendant held by a
  local criminal court for the action of a grand jury,  order  such  grand
  jury reconvened for the purpose of dealing with a matter requiring grand
  jury action.