The Minnesota DWI Case Of The Week is Knapp V. Commissioner of Public Safety (Decided November 12, 2026 Minn.),wherein the Minnesota Supreme Court was asked to decide whether or not a deficient observation period automatically excludes the data master breath test result. And the short answer from the Supreme Court was: No. "The district court must consider all record evidence bearing on whether the breath sample was contaminated and must admit the test result if a preponderance of the evidence shows that the breath sample was not contaminated".
In Knapp, the appellant was arrested on suspicion of driving while impaired (DWI) and consented to a breath test that showed his alcohol concentration exceeded the legal limit. Knapp challenged the revocation on the sole ground that the arresting officer conducted an inadequate pre-test observation period.
The district court found that the observation period was inadequate and that Knapp’s test result was inadmissible. The Court of Appeals reversed, holding that the district court abused its discretion in ruling the test result was inadmissible based solely on evidence of an imperfect observation period. The Minnesota Supreme Court reversed the Court of Appeals and sent the case back down to the district court for further findings.
Knapp argued that a test result can be admitted without antecedent expert testimony establishing that the breath testing instrument provided a trustworthy and reliable measure of alcohol concentration in the breath sample only if all protocols necessary to establish reliability were properly performed in the particular case. Knapp asserted that an adequate observation period is one of the protocols required for admissibility. It was Knapp's claim that without an adequate observation period, the breath test result must automatically be excluded.
The Commissioner of Public Safety Agreed that test result admissibility requires considering whether the breath test was properly administered in the particular case. The Commissioner, however, argued that this consideration is limited to the administration or use of the instrument.
The Commissioner asserted that the observation period is not a protocol related to the use of the instrument. Consequently, if the record shows that a trained operator properly followed all steps needed to operate an approved instrument, the breath test results that the instrument generates are admissible.
The Minnesota Supreme Court disagreed with both Knapp and the Commissioner of Public Safety, finding that an inadequate observation period does not per se result in the exclusion of the breath test. Rather, the Supreme Court held that the district court must look at all the evidence to determine whether or not the breath test result is reliable. Or, as stated by the Minnesota Supreme Court:
"In summary, based on our analysis of the relevant cases and Minn. Stat. §634.16, we conclude that the risk that a breath sample was contaminated could support a district court determination that the breath test result reached with that sample is inadmissible, but that such a determination must be based on all record evidence bearing on whether the sample was contaminated, with the proponent of admissibility bearing the burden under a preponderance of the evidence standard. An imperfect observation is not a per se reason to exclude the breath test result."
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"For admissibility purposes, the proponent may establish foundation that the breath-test instrument accurately and reliably analyzed a breath sample and reported an alcohol-concentration measurement from that sample without expert testimony if two conditions are met: (1) the instrument has been approved by the Commissioner, and (2) the person operating the instrument was fully trained pursuant to Commissioner-approved training.17 Minn. Stat. § 634.16; Quinn, 182 N.W.2d at 845.
The proponent of admitting a breath test must also establish foundation that the breath test was properly administered in the particular case, including that the breath test provided a reliable measure of the alcohol content of the driver’s deep lung breath. Dille, 258 N.W.2d at 567. Under our alcohol-content-test-result-admissibility precedent, flaws in administering a breath test do not decisively establish that the breath-test result is inadmissible because it lacks foundational reliability. Id. at 567–68; Habisch, 313 N.W.2d at 16. Rather, the test result may be admissible if sufficient record evidence shows that the reliability purposes that the allegedly flawed protocol serves—here, preventing test results that are not a measure of the alcohol concentration in the driver’s deep lung breath—were met. Dille, 258 N.W.2d at 568.
In assessing whether a breath-test result is admissible, and specifically whether the breath sample tested was not contaminated so as to provide a reliable measure of the alcohol content of the driver’s deep lung breath, a district court should consider all the evidence bearing on that question. Ultimately, when a defendant challenges a test sample on the ground that it may have been contaminated, the district court should assess admissibility under a preponderance of evidence standard, asking whether it is more likely than not that the test results reflect a reliable measure of the alcohol concentration of a driver’s deep lung breath."
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"The purpose of an observation period, like the sterilization of a needle and bottle in Dille, is to prevent sample contamination. Thus, the question in this case is whether all pertinent evidence shows, by a preponderance of evidence, that Knapp’s breath sample accurately tested deep lung air—i.e., it was not contaminated. If the answer is “Yes,” then the district court should admit the test-result evidence.
In answering this question here, we decline to adopt the court of appeals’ position that Knapp’s failure to introduce direct affirmative evidence of mouth alcohol means the breath test is admissible. As discussed above, the burden is on the Commissioner to prove by a preponderance of the evidence that Knapp’s breath sample was not contaminated. Under our precedent on the admissibility of test results for alcohol concentration, we also reject Knapp’s position that an inadequate observation period, standing alone, is dispositive of admissibility. Inadequacies in an observation period are one factor to consider in assessing, under the preponderance of the evidence standard, whether it is more likely than not that a breath sample was not contaminated."
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"...we conclude that the district court abused its discretion when it determined that Knapp’s test result was unreliable because the court did not apply the appropriate analysis in assessing the test result’s foundational reliability and, consequently, based its decision on an erroneous view of the law. The district court remains, however, in the best position to make that determination under the proper standard articulated in this opinion. Therefore, we remand to the district court to determine whether Knapp’s breath-test results are admissible under the standard we articulate today."
Moral Of The Story: Law enforcement is on notice that they need to pay attention!
If you or a loved one have been charged with a Minnesota DWI, feel free to contact Minneapolis DWI Attorney, F. T. Sessoms at (612) 344-1505 for answers to all of your Minnesota DWI and DUI questions.
