Minnesota Supreme Court limits challenges to breathalyzer tests

People who are or were arrested for drunk driving in Minnesota lost a bid today to fight their charges on the basis of errors in the instrument used to administer breathalyzer test.

The Intoxilyzer 5000EN uses infrared absorption spectroscopy to measure the breath alcohol concentration of subjects who provide breath samples. But last year, Minnesota acknowledged there’s a problem with the source code in the unit, prompting Minnesotans to start challenging their arrests.

Today, a sharply divided Minnesota Supreme Court turned aside the challenges, upholding a district court finding based on a state’s expert witness that the instrument “produced valid breath alcohol measurements and functioned as designed.”

But nearly a half-dozen other experts concluded otherwise when the district court held a hearing. But in his opinion today, Justice Barry Anderson dismissed those claims. “Based on this record, we conclude that a preponderance of the evidence supports the district court’s pretrial determination that Intoxilyzer 5000EN instruments that report a numerical value for measured breath alcohol are reliable and unaffected by the source code errors alleged at the evidentiary hearing.”

“I have concerns regarding the practical effect of these rulings to the extent they essentially eviscerate the opportunity for an accused to challenge the weight or credibility of Intoxilyzer 5000EN results,” Justice Alan Page wrote in a dissenting opinion. He says even the proximity of a cellphone at the time of the test could influence the results, but a person charged with drunk driving couldn’t full admit into evidence the reliability of the breathalyzer.

“The practical result of the court’s holdings is that defendants will be unable to challenge Intoxilyzer 5000EN results,” Justice Page said. “Despite evidence that the test has a margin of error, that radio frequencies from cell phones can disturb the accuracy of the test, and that the test may erroneously produce a deficient sample,4 a defendant may not raise the source code as a potential cause of an inaccurate or deficient sample. Denying the accused an opportunity to raise source code issues effectively eliminates the accused’s opportunity to challenge the results.”

Two other justices — Helen Meyer and Paul Anderson — joined in Page’s dissent.

The full opinion is here.