The application of the Fourth Amendment's protection against warrantless searches and the Fifth Amendment privilege against self incrimination to searches that intrude into the human body means that police may not conduct warrantless blood testing on suspects absent an emergency that justifies acting without a warrant. Decided June 20, 1966 (argued April 25, 1966). Opinion of the Court: William J. Brennan → go there Dissenting: Warren, Black, Douglas. Topic: Fourth Amendment rights. Schmerber v. California, 384 U.S. 757 (1966), is a landmark United States Supreme Court case in which the Court clarified the application of the Fourth Amendment's protection against warrantless searches and the Fifth Amendment right against self-incrimination for searches that intrude into the human body. Until Schmerber, the Supreme Court had not yet clarified whether state police officers must procure a search warrant before taking blood samples from criminal suspects. Likewise, the Court had not yet clarified whether blood evidence taken against the wishes of a criminal suspect may be used against that suspect in the course of a criminal prosecution. Wiki link