Missouri v. McNeely

Whether evidence obtained by a nonconsensual and warrantless blood sample from a drunk driver is admissible under the exigent circumstances exception to the Fourth Amendment warrant requirement based upon the natural dissipation of alcohol in the bloodstream.

A Missouri state patrolman stopped Respondent for speeding and arrested him for DWI. After Respondent refused voluntary breath and blood tests, the officer drove Respondent to the hospital and obtained a non-consensual and warrantless blood sample. The trial court granted a motion to suppress, stating that the blood sample was obtained in violation of the Fourth Amendment unless an exigent circumstance existed—specifically a car accident or an injury. The Missouri Court of Appeals reversed, holding that the "evanescent nature" of alcohol in blood was a valid exigent circumstance. The Missouri Supreme Court reversed the Court of Appeals and affirmed the trial court.

On appeal the State argues that there is deep division among state courts on what Schmerber stands for that will likely continue to divide courts throughout the United States until the Supreme Court clarifies its holding.