Blinding Them With Science: Attacking Breath Tests

Posted On November 19, 2013 by Daniel Koewler

Minnesota DWI defense is at a crossroads. In the wake of Missouri v. McNeely and State v. Brooks, every blood, breath and urine test can face a direct challenge from skilled defense attorneys, raising the question of whether or not the driver "freely and voluntarily" consented to a warrantless search of their body.

But this type of challenge isn't the only defense to a DWI. We've been practicing DWI defense for a long time - long before Brooks, and long before McNeely. And while we've led the way in raising (and winning) these constitutional challenges to blood, breath and urine tests, there is more than one way to win a case - many times, by the expert use of science (if you only follow one link in this post, click on that one).

Now, take a look at this order. If you don't want to read through a dense legal decision, I'll cut to the chase and tell you what it says: after days of expert testimony, an Ohio judge ruled that breath tests on Ohio's breath test device "are not scientifically reliable, and the Court, as the gate-keeper against un-scientific evidence, must prohibit them from being introduced into evidence in this case."

That is a very compelling holding. The Court concluded that the machine being used in Ohio could potentially produce false results due to interference from smart phones, due to manipulation of the test by the officer, and due to fundamental failures in the sampling process.

These are just some of the challenges that can be raised to a specific breath test device, challenges that are just as potent against Minnesota's DataMaster DMT as they are against Ohio's breath test machine. And we should know - we've actually been to the factory that makes them, and both Chuck and yours truly are certified as "competent to operate and perform essential diagnostic verifications" on the instrument.

Challenges to the constitutionality of a DWI alcohol concentration test are absolutely essential to raising a proper defense to the charge of driving while intoxicated. But it is just as important to make sure that the scientific basis behind these tests are being challenged in every appropriate circumstance as well.