Minnesota Supreme Court clarifies rules on breathalyzer test results

(FOX 9) - The Minnesota Supreme Court issued a major ruling on Thursday that will change how courts decide if breathalyzer tests can be used in DWI court cases.

The decision

Big picture view:

The justices vacated rulings by the Court of Appeals and district court in Derek Alexander Knapp’s case against the Commissioner of Public Safety.

Knapp is challenging the admissibility of a breath-test result that led to his driver’s license being revoked after his 2023 arrest. The test reported an alcohol concentration of 0.08. The case concerns his license revocation, not an appeal of a criminal case.

Minnesota DWI breathalyzer requirements

What we know:

The case centers on an observation period that officers are trained to carry out before conducting a breathalyzer test.

During that time, officers watch for burping, belching or regurgitating stomach contents, which can impact a breathalyzer test.

That's because the concentration of alcohol in the stomach can be 2,000 times stronger than the alcohol concentration in air from the lungs.

Officers are trained to observe suspected drunk drivers for 15 minutes before using a breathalyzer.

Legal challenge to Minnesota breath test standards

The backstory:

During oral arguments, attorneys challenging state law said it doesn't mandate how that observation is carried out.

"That's why we're here today, because we are here to address what is a proper observation. And how necessary is it for the reliability of a breath test," said Robert M. Christensen, an attorney challenging the DWI breathalyzer standards.

Christensen argued that officers must closely monitor suspected drunk drivers for 15 minutes to ensure mouth alcohol does not contaminate a breath sample and skew the results.

Minnesota Supreme Court DWI ruling

Why you should care:

The Supreme Court decision on Thursday rejected Court of Appeals guidelines that placed the burden on drivers to show their samples were contaminated. Instead, judges said the state is responsible for proving that a sample was reliable.

What they're saying:

The Supreme Court did not issue a final ruling in Knapp's case, instead sending it back to the district court to rule on the admissibility of the breath test using the Supreme Court's standard.

The Source: This story uses information from the court case and Court of Appeals and Minnesota Supreme Court filings.