The Arizona Supreme Court ruled Thursday that, in most cases, police cannot take blood samples from an unconscious DUI suspect without obtaining a search warrant.

The ruling weighed the constitutionality of a state law allowing warrantless blood draws in suspected DUI cases in which a driver is dead, unconscious or otherwise incapable of refusing to grant permission. The ruling does make an exception if the police are facing urgent circumstances — beyond the normal process of metabolizing alcohol in the body, that is.

The Arizona high court said its 3-2 decision tracks a 2013 U.S. Supreme Court ruling on warrantless blood draws and Fourth Amendment privacy rights of DUI suspects.

The decision said a Mohave County judge erred in refusing to bar use of a blood sample taken from a man after a 2012 crash because state troopers could have obtained a warrant but didn't.