The decision of a USMJ to issue a search warrant is reviewed by the District Court for “clear error” in the Ninth Circuit. United States v. Alvarez, 2016 U.S. Dist. LEXIS 75970 (N.D.Cal. June 10, 2016):
Where a judge has issued a search warrant, that decision is reviewed “for clear error.” United States v. Fernandez, 388 F.3d 1199, 1252 (9th Cir. 2004), as modified, 425 F.3d 1248 (9th Cir. 2005). Deference is given to the judge’s determination, and the reviewing court asks whether “the [judge] had a substantial basis to conclude that the warrant was supported by probable cause.” Id.; see also United States v. Vargem, 566 F. App’x 580, 581 (9th Cir. 2014) (“The district court did not err in holding that the magistrate judge who issued the search warrant had a ‘substantial basis to conclude that the warrant was supported by probable cause'”). Whether there is probable cause is a “commonsense practical question,” requiring “[n]either certainty nor a preponderance of the evidence.” United States v. Kelley, 482 F.3d 1047, 1050 (9th Cir. 2007). Where a judge has found probable cause, this “will not be reversed absent a finding of clear error.” United States v. Pitts, 6 F.3d 1366, 1369 (9th Cir. 1993).
Applying this standard here, the Court upholds the warrant as supported by probable cause.