Cal. Civ. Proc. Code § 1250.330

Where a party is represented by an attorney, his pleading need not be verified but shall be signed by the attorney for the party. The signature of the attorney constitutes a certificate by him that he has read the pleading and that to the best of his knowledge, information, and belief there is ground to support it. If the pleading is not signed or is signed with intent to defeat the purposes of this section, it may be stricken.