Breathalyzers v. Blood-Alcohol Tests

Jenny Nomura, MJLST Managing Editor

In the MJLST volume 11 spring edition, David Liebow discussed the difficulties of obtaining the source code of breathalyzers in DWI cases. In his note “DWI Source Code Motions after Underdahl” Liebow argues for easier breathalyzer source code access for DWI defendants. Obtaining the breathalyzer source code could help DWI defendants show the unreliability of the machine. In the years following the note, not much appears to have changed. And in some states it might not change for a long time, if ever.

The Minnesota Supreme Court received a case in which the source code of the Intoxilyzer 5000EN was in question (In re Source Code Evidentiary Hearings in Implied Consent Matters, 816 N.W.2d 525 (Minn. 2012)). The District Court had accepted the testimony of the state’s expert witness that the device was accurate, and the Minnesota Supreme Court affirmed that holding. In a dissent, Justice Page stated that “a defendant may not raise the source code as a potential cause of an inaccurate or deficient sample.” Other states have reached a very different conclusion: that maybe breathalyzers shouldn’t be relied on. In Pennsylvania, a county judge held breathalyzers were not accurate above a reading of 0.15.

So what does the future hold for breathalyzers? There is a tangle of recent case law that might play a role in determining whether police use breathalyzers or blood-alcohol tests. In Pennsylvania, police have switched from relying on breathalyzers to blood-alcohol tests in response to the county judge ruling. However, in a recent United States Supreme Court case, Missouri v. McNeely, 133 S. Ct. 1552 (2013), the Court held police must obtain a search warrant or have exigent circumstances to have a blood-alcohol test done for a person arrested for a DWI. That case seems to push police back to relying on breathalyzers. But the Minnesota Supreme Court held in Minnesota v. Brooks, 838 N.W.2d 563 (Minn. 2013) that Brooks gave consent voluntarily and freely at the time of the arrest to submit to the blood-alcohol test, and therefore the police didn’t need a search warrant or exigent circumstances.

If police officers are able to obtain a blood-alcohol test, then the prosecution might not need to rely on the breathalyzer results in order to obtain a conviction. If the breathalyzer results “don’t matter” (“don’t matter” in the sense that the results aren’t used as evidence in court) then maybe the source code of the breathalyzer machines also “doesn’t matter.” Maybe the new focus will be on the blood-alcohol tests.