Cal. Code Civ. Proc. § 482.040
The facts stated in each affidavit filed pursuant to this title shall be set forth with particularity. Except where matters are specifically permitted by this title to be shown by information and belief, each affidavit shall show affirmatively that the affiant, if sworn as a witness, can testify competently to the facts stated therein. As to matters shown by information and belief, the affidavit shall state the facts on which the affiant's belief is based, showing the nature of his information and the reliability of his informant. The affiant may be any person, whether or not a party to the action, who has knowledge of the facts. A verified complaint that satisfies the requirements of this section may be used in lieu of or in addition to an affidavit.
Ca. Civ. Proc. Code § 482.040