What is the standard for establishing that an affidavit is falsified?

The Franks v. Delaware standard has emerged as a two-pronged test to be applied by the courts. First, defendant must make a substantial preliminary showing that the affidavit contains an actual and deliberate falsity. Second, the court must determine whether the challenged statement is necessary to a finding of probable cause. United States v. Davis, 714 F.2d 896 (9th Cir.1983).