487 U.S. 533 (1988)
Federal agents were surveilling Michael F. Murray and several co-conspirators based on information from informants.1 At about 1:45 p.m. on April 6, 1983, the agents observed Murray drive a truck and James D. Carter drive a green camper into a warehouse in South Boston.2 When the vehicles left about twenty minutes later, the agents saw within the warehouse two individuals and a tractor-trailer rig bearing a long, dark container.3
Murray and Carter later turned over the truck and camper to other drivers; those drivers were followed, arrested, and the vehicles were lawfully seized and found to contain marijuana.4 After receiving this information, several agents converged on the South Boston warehouse and forced entry.5 They found the warehouse unoccupied but observed in plain view numerous burlap-wrapped bales that were later found to contain marijuana.6
The agents left without disturbing the bales, maintained surveillance, and did not reenter until they had a search warrant.7 In applying for the warrant, the agents did not mention the prior entry and did not rely on observations made during that entry.8 The warrant issued at 10:40 p.m., approximately eight hours after the initial entry; the agents immediately reentered the warehouse and seized 270 bales of marijuana and notebooks listing customers.9
Before trial, petitioners moved to suppress the warehouse evidence.10 The District Court denied the motion, rejecting claims that the warrant was invalid because the agents did not inform the Magistrate of their prior warrantless entry and that the warrant was tainted by that entry.11 The First Circuit affirmed, assuming for purposes of decision that the first entry was unlawful.12 The cases were consolidated and brought to the Supreme Court.13
The District Court did not explicitly find that the agents would have sought a warrant if they had not earlier entered the warehouse.14
Whether the independent source doctrine permits the admission of evidence initially observed during an unlawful search but later seized pursuant to a warrant obtained without reliance on information from the unlawful search?15
The exclusionary rule prohibits introduction into evidence of tangible materials seized during an unlawful search and testimony concerning knowledge acquired during an unlawful search.16 Beyond that, the rule also prohibits derivative evidence if it is the product of the primary evidence or otherwise acquired as an indirect result of the unlawful search.17 The independent source doctrine recognizes that society's interest in deterring unlawful police conduct must be balanced against the public interest in having juries receive all probative evidence of a crime.18 When challenged evidence has an independent source, exclusion would put the police in a worse position than they would have been in absent any error or violation.19 The doctrine applies even when evidence is initially discovered during an unlawful search but later obtained independently from activities untainted by the initial illegality.20
Yes. The independent source doctrine permits admission of the warehouse evidence because the agents acquired knowledge of the marijuana through the subsequent warrant search that was genuinely independent of the initial unlawful entry.21
The warrant application omitted any reference to the prior entry or observations made during it.22
The warrant issued at 10:40 p.m. after the initial entry, and the agents reentered only after obtaining it, seizing 270 bales and notebooks.23
The dispositive question remains whether the agents' decision to seek the warrant was prompted by what they had seen during the initial entry, a determination the District Court must make on remand.24
The judgment is vacated and the cases are remanded to the Court of Appeals with instructions to remand to the District Court for determination whether the warrant-authorized search was an independent source of the challenged evidence.25
Related opinions on this issue
Justice Marshall dissents on the ground that the majority's extension of the independent source exception fails to provide sufficient guarantees that the subsequent search was actually independent, emasculates the Warrant Clause, and undermines the deterrent function of the exclusionary rule.26 He emphasizes that the agents made no effort to obtain a warrant prior to the initial entry, had not prepared a warrant affidavit, and had not discussed obtaining one.27 The same team of investigators conducted both searches immediately after the illegal entry, and the affidavit was prepared by a participant in the initial search.28
Under these circumstances, admitting the reseized evidence creates an incentive for officers to conduct confirmatory illegal searches first, secure in the knowledge that they can later obtain a warrant while omitting any mention of the illegality.29 The litigation risk concerning officers' subjective intent provides an inadequate deterrent, and the exception should not apply when no verifiable historical facts establish true independence.30
Justice Stevens joins Justice Marshall's opinion explaining why the majority's extension of Segura v. United States weakens the Warrant Clause and provides an incentive for warrantless searches.31 He remains convinced that Segura itself was unacceptable because it provided agents with an affirmative incentive to engage in unconstitutional invasions of the home.32 The Court has taken another step toward law enforcement unfettered by process concerns, and he regrets that choice.
In due course he hopes the Court will recall that courts should not aid law enforcement at the expense of fundamental constitutional protections.33