California v. Greenwood

On 11 January 1988, the case was argued before the Supreme Court and was decided on 16 May 1988. Greenwood's lawyer, Michael Ian Garey, argued that Greenwood had an expectation of privacy regarding the trash that he had placed on the curb in opaque plastic bags, and had assumed would be collected, mixed with other trash, and taken to the dump. In theory, the Fourth Amendment protects people's rights to privacy. Justice White, writing for the majority of six, stated that the expectation of privacy does not guarantee protection by the Fourth Amendment unless society considers that expectation to be reasonable. White explained, "It is common knowledge that plastic garbage bags left on or at the side of a public street are readily accessible to animals, children, scavengers, snoops, and other members of the public." Greenwood had placed the bags on the curb in order to convey them to the trash collector, who could have sorted through them or allowed the police to do so. Because the bags of trash were deposited in an area particularly suited for public inspection, the expectation of privacy was not objectively reasonable.

Greenwood's lawyer also argued that the expectation of privacy should be considered reasonable because under the Krivda ruling, searches and seizures of trash, done without warrants, were illegal under California law. He also argued that a California constitutional amendment eliminated the exclusionary rule for evidence seized in violation of state, but not federal, law. Garey claimed that the California amendment violated the Due Process Clause of the Fourteenth Amendment, meaning that the government may not deprive anyone of life, liberty, or property without a fair trial or hearing.

White countered that California could amend its constitution to negate the decision in the Krivda case. He stated that "at the federal level, we have not required that evidence obtained in violation of the Fourth Amendment be suppressed in all circumstances." White noted that decisions made about excluding evidence, based on the Fourth Amendment, have weighed the benefits of preventing police misconduct against the costs of excluding reliable evidence. The Court has declined to apply the exclusionary rule when law officers have acted in good faith and when the benefit to the guilty defendant would go against the basic concepts of the criminal justice system. White suggested that the states could take a similar position balancing the benefits of excluding relevant evidence of criminal activity against the costs, as long as the police have not violated federal law. Based on these opinions, the majority ruled to reverse the decision of the California Court of Appeals, deciding, along with the "vast majority of lower courts that have addressed the issue," that the Fourth Amendment does not prohibit the warrantless search and seizure of garbage left for collection.