A party is not entitled to present its case at a hearing on a motion to suppress by affidavit instead of live testimony. The prosecution tried to meet its burden of proof at a suppression motion by presenting an affidavit of the officer who conducted the search. There was no contention of unavailability. The Supreme Court held the language of Penal Code sections 1538.5 and 1539 show the statutes clearly contemplate a hearing at which live witnesses testify whose demeanor and credibility can be evaluated by a judge or magistrate. The court rejected the arguments that affidavits were authorized under section 2009 of the Code of Civil Procedure or under Penal Code section 1204.5.