Is a warrant valid for a search conducted pursuant to a warrant?

Whether a warrant complies with the constitutional requirement of particularity is a question of law, subject to our independent review, although we must defer to the trial court's determination of the facts so long as those findings are supported by substantial evidence. (People v. Amador, supra, 24 Cal.4th at p. 393.) Strong policy favors searches conducted pursuant to a warrant rather than those undertaken on some other allowable basis and, for this reason, a warrant is presumed to have been valid. (Ibid.) Accordingly, a defendant who challenges a warrant's sufficiency bears the burden of establishing that its errors and omissions are fatal to its enforceability. (See ibid.)