2005 California Code of Civil Procedure Sections 389-389.5 CHAPTER 8. COMPULSORY JOINDER

389.  (a) A person who is subject to service of process and whose
joinder will not deprive the court of jurisdiction over the subject
matter of the action shall be joined as a party in the action if (1)
in his absence complete relief cannot be accorded among those already
parties or (2) he claims an interest relating to the subject of the
action and is so situated that the disposition of the action in his
absence may (i) as a practical matter impair or impede his ability to
protect that interest or (ii) leave any of the persons already
parties subject to a substantial risk of incurring double, multiple,
or otherwise inconsistent obligations by reason of his claimed
interest.  If he has not been so joined, the court shall order that
he be made a party.
   (b) If a person as described in paragraph (1) or (2) of
subdivision (a) cannot be made a party, the court shall determine
whether in equity and good conscience the action should proceed among
the parties before it, or should be dismissed wihout prejudice, the
absent person being thus regarded as indispensable.  The factors to
be considered by the court include:  (1) to what extent a judgment
rendered in the person's absence might be prejudicial to him or those
already parties; (2) the extent to which, by protective provisions
in the judgment, by the shaping of relief, or other measures, the
prejudice can be lessened or avoided; (3) whether a judgment rendered
in the person's absence will be adequate; (4) whether the plaintiff
or cross-complainant will have an adequate remedy if the action is
dismissed for nonjoinder.
   (c) A complaint or cross-complaint shall state the names, if known
to the pleader, of any persons as described in paragraph (1) or (2)
of subdivision (a) who are not joined, and the reasons why they are
not joined.
   (d) Nothing in this section affects the law applicable to class
actions.
389.5.  When, in an action for the recovery of real or personal
property, or to determine conflicting claims thereto, a person not a
party to the action but having an interest in the subject thereof
makes application to the court to be made a party, it may order him
to be brought in by the proper amendment.