[2] At the trial court, Mitchell made a motion to suppress the results of the hospital blood draw on the grounds that it was a warrantless search and thus unconstitutional under the Fourth Amendment.

The prosecutor argued that Wisconsin's state laws constitute implied consent to blood draws once someone begins driving a vehicle.

[3] In a 5–2 decision written by Chief Justice Roggensack, the Wisconsin Supreme Court upheld Mitchell's conviction, answering that the "implied consent" rule was constitutional, and thus the blood draw was permissible under the Fourth Amendment.

In it, he argued that the "implied consent" rule is unconstitutional, but that the exigent circumstances doctrine, along with United States Supreme Court precedent, allow for a warrantless blood draw from an unconscious driver who is suspected of being intoxicated.

[4] Mitchell applied for certiorari before the United States Supreme Court, which accepted the case to decide "[w]hether a statute authorizing a blood draw from an unconscious motorist provides an exception to the Fourth Amendment warrant requirement."