United States v. Smith was a United States Supreme Court case that dealt with the issue of whether a defendant could be convicted of a crime if the evidence presented at trial was obtained through an illegal search and seizure. The Court held that the evidence was inadmissible and that the defendant could not be convicted. The case arose when the defendant, Smith, was arrested for possession of stolen goods. The police had searched Smith's home without a warrant and had seized the stolen goods. Smith argued that the search and seizure were illegal and that the evidence should not be used against him. The government argued that the evidence was admissible because it was obtained in good faith. The Supreme Court held that the evidence was inadmissible and that the defendant could not be convicted. The Court reasoned that the Fourth Amendment of the United States Constitution protects citizens from unreasonable searches and seizures and that the evidence obtained in this case was obtained in violation of the Fourth Amendment. The Court also held that the good faith exception to the exclusionary rule did not apply in this case because the police had acted in bad faith. The Court's decision in United States v. Smith established that evidence obtained through an illegal search and seizure is inadmissible and that a defendant cannot be convicted based on such evidence. This decision has been cited in numerous cases since then and has become an important part of Fourth Amendment jurisprudence.

Justice Field delivered the dissenting opinion in United States v. Smith, arguing that the majority's decision was contrary to both law and justice. He argued that Congress had not intended for a defendant to be convicted of two offenses when they were committed as part of one continuous act or transaction. In this case, he noted that Smith had been charged with two counts of selling liquor without a license on different days but from the same location; thus, it could be argued that these acts constituted one offense rather than two separate ones. Furthermore, Justice Field pointed out that if Smith had been found guilty on both counts then he would have received an excessive punishment since his actions did not warrant such severe consequences under either count alone. As such, Justice Field concluded by stating his belief that the Court should reverse its ruling and find in favor of Smith due to lack of evidence supporting multiple convictions for what appeared to be a single offense.