Does a search warrant need to be obtained prior to the search warrant being issued?

"United States v. Griffin, (502 F.2d 959 (6th Cir. 1974)), involved the unlawful search and seizure of a dwelling by police, while other officers secured a search warrant. Although a warrant based upon previously obtained information was issued and executed, the evidence was nevertheless suppressed. Rejecting the government's contention that the evidence unlawfully seized would have been 'inevitably discovered' pursuant to the search warrant, the court concluded that exclusion of the evidence was the only practical means of deterring unlawful police conduct.