Armando Schmerber (defendant) crashed his car into a tree and injured both himself and his passenger. The police officer who responded to the scene smelled alcohol on Schmerber's breath and noticed that Schmerber's eyes looked bloodshot and glassy. Schmerber and his passenger were transported to the hospital for treatment. At the hospital, within two hours after the accident, the same officer saw Schmerber again and saw similar signs that Schermber was drunk. Schmerber refused to give a blood sample for chemical analysis, so the officer directed a doctor to take one anyway. The analysis showed that Schmerber was intoxicated at the time of the accident. Schmerber was tried for driving while under the influence of alcohol, and the analysis was entered into evidence. Schmerber objected, claiming that the forced withdrawal of his blood violated his Fifth Amendment privilege against self-incrimination and his Fourth Amendment right not to be subjected to unreasonable searches and seizures. Schmerber was convicted of driving under the influence of alcohol. The appellate court affirmed Schmerber's conviction, and the United States Supreme Court granted certiorari.