California Code, Code of Civil Procedure - CCP § 484.360

(a) If the defendant files and serves a claim of exemption and the plaintiff desires to oppose the claim, he shall file and serve on the defendant, not less than two days before the date set for the hearing, a notice of opposition to the claim of exemption, accompanied by an affidavit supporting any factual issues raised and points and authorities supporting any legal issues raised.

(b) If the defendant files and serves a claim of exemption and supporting affidavit as provided in Section 484.350 and the plaintiff does not file and serve a notice of opposition as provided in this section, no writ of attachment shall be issued as to the property claimed to be exempt. If all of the property described in the plaintiff's application is claimed to be exempt and the plaintiff does not file and serve a notice of opposition as provided in this section, no hearing shall be held and no writ of attachment shall be issued.

(c) If the plaintiff files and serves a notice of opposition to the claim as provided in this section, the defendant has the burden of proving that the property is exempt from attachment.