A new United States Supreme Court ruling has probably rendered some Texas DWI laws unconstitutional and will have a big impact on the way DWI investigations are conducted in many cases. That case, Missouri v. McNeely, involved a DWI suspect who refused to provide a blood test. Blood was obtained anyway, and the police did not obtain a warrant prior to doing so, relying on the “exigent circumstances” exception to the rule that a warrant is required.

Earlier this month, the Supreme Court ruled that Missouri’s approach was contrary to the Constitution. While the case did not go so far as to say that the police must always get a warrant, the justices did say that there is no rule that allows the police to get blood in every DWI case without a warrant. Specifically, the majority opinion concluded that the fact that alcohol in the blood dissipates over time is not necessarily enough to create an “exigent circumstance.” The ruling will require that each case be judged on its own facts and from a law enforcement perspective, getting a warrant makes even more sense.

Several justices were understandably uncomfortable with the government having free-reign to subject citizens to the forced blood draws in every DWI case (Chief Justice Roberts referred to the “pretty scary image” of forced blood draws).

In Texas, several categories of DWIs or other intoxication offenses are subject to “mandatory” blood draws including cases where the Defendant has two prior convictions, or some cases where there is an accident involving injury. These provision of the Texas Transportation Code are now on shaky Constitutional ground, and the State will have to show exigency to justify these blood draws.

Interestingly, in Harris County and many other places, it is now easier than ever for the police to obtain search warrants to conduct mandatory blood draws. This is largely because of the expansion of the “no refusal” program has led to a very efficient infrastructure for obtaining warrants and has probably limited the situations where an “exigency” would actually require the taking of blood without a warrant.

-Jose Ceja