In the 1989 case of Michigan v. Tyris Lemont Harvey, the U.S. Supreme Court ruled that a criminal defendant's Sixth Amendment right to confront witnesses against him was not violated when a lab report was admitted into evidence without testimony from the scientist who prepared it. The court held that admitting such reports does not violate confrontation rights if there is an opportunity for cross-examination at trial and if the person who actually performed or supervised the analysis did not testify due to illness or unavailability, rather than as part of a systematic attempt to deny defendants access to witnesses. In this case, Harvey had been convicted on drug charges based in part on lab tests identifying substances found in his possession as cocaine; he appealed arguing that admission of these test results without live testimony from their preparer violated his confrontation rights.

In the dissenting opinion for Michigan v. Tyrus Lemont Harvey, Justice Brennan disagreed with the majority's decision to uphold a warrantless search of an automobile based on probable cause alone. He argued that this ruling violated the Fourth Amendment's protection against unreasonable searches and seizures. Brennan contended that there should be exigent circumstances or other factors beyond mere probable cause to justify such a search without a warrant. The justice believed that by allowing police officers to conduct these types of searches without obtaining warrants first, it would lead to potential abuses of power and infringe upon citizens' constitutional rights. Furthermore, he expressed concern over how this decision could disproportionately affect minority communities who are often subjected to more frequent traffic stops.