The U.S. Supreme Court decided the case Missouri v. McNeely on Wednesday, ruling that states may not automatically draw blood from DWI suspects. Missouri argued that the natural metabolization of alcohol justified drawing blood from DWI suspects in all cases without a warrant. The Supreme Court disagreed, finding that the potential dissipation of blood alcohol did not override the 4th Amendment’s warrant requirement. The Court, did however, state that the need for a warrant must be determined on a case by case basis and that states could adopt rules and procedures to satisfy 4th Amendment concerns. The Court did not provide any guidance as to what those rules might look like, so we’re sure to see more blood drawing cases before the Court in the future.