487 U.S. 533 (1988)
Facts: Based on the tips received from informants, federal agents were surveilling Murray (“Defendant”) for illegal drug activities. During that surveillance, the agents observed Defendant and another individual driving vehicles into, and later out of, a warehouse, and, upon their exit, the officers saw that the warehouse contained a tractor-trailer rig bearing a long container. Defendant and his accomplice later turned over their vehicles to other drivers, who were in turn followed and ultimately arrested, and the vehicles were lawfully seized and found to contain marijuana.
After receiving information about those arrests and what was discovered in the vehicles, several agents forced their way into the warehouse and observed in plain view numerous burlap-wrapped bales. The agents left without disturbing the bales and did not return until they had obtained a warrant to search the warehouse.
In applying for the warrant, the agents did not mention the prior entry into the warehouse or include any recitations of their observations made during that entry. Upon issuance of the warrant, they reentered the warehouse and seized 270 bales of marijuana and other evidence of crime.
Holding: The United States Supreme Court held that since the warrant was obtained based on information independent of the first warrantless entry, the evidence obtained pursuant to the warrant was admissible.
The Court applied the “independent source doctrine” and described its scope and application as follows:
“Our cases have used the concept of ‘independent source’ in a more general and a more specific sense. The more general sense identifies all evidence acquired in a fashion untainted by the illegal evidence-gathering activity. Thus, where an unlawful entry has given investigators knowledge of facts x and y, but fact z has been learned by other means, fact z can be said to be admissible because derived from an ‘independent source’ . . . The original use of the term, however, and its more important use for purposes of this case, was more specific. It was originally applied in the exclusionary rule context, by Justice Holmes, with reference to that particular category of evidence acquired by an untainted search which is identical to the evidence unlawfully acquired — that is, in the example just given, to knowledge of facts x and y derived from an independent source[.]” Id. at 538.
The Court further explained:
“To determine whether the warrant was independent of the illegal entry, one must ask whether it would have been sought even if what actually happened had not occurred — not whether it would have been sought if something else had happened. That is to say, what counts is whether the actual illegal search had any effect in producing the warrant, not whether some hypothetical illegal search would have aborted the warrant. Only that much is needed to assure that what comes before the court is not the product of illegality; to go further than that would be to expand our existing exclusionary rule.” Id. at 542 n. 3.
Applying the foregoing principles to the case, the Court held that the evidence obtained in the warehouse pursuant to the warrant was admissible.