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A faulty breath test can support a challenge to a Minnesota DWI charge, but it does not automatically require dismissal. Counsel must identify an actual legal or reliability problem, determine its effect on the evidence and assess what other proof remains.
Which breath test are you challenging?
A roadside preliminary breath test and an evidentiary DataMaster DMT test serve different purposes. Section 169A.41 limits use of preliminary screening results, with specified exceptions. Do not assume that every number in the police report is the evidentiary result used for the charged offense.
What records help evaluate the result?
The BCA DataMaster DMT operator manual provides a technical reference for reviewing testing procedures. A useful review examines the actual test record and applicable protocol rather than relying on a general list of supposed breathalyzer flaws.
- Test documents: The complete test record, times, instrument messages and any interrupted or repeated tests.
- Procedure: Operator qualifications, observation-period documentation and recordings of the testing process.
- Instrument records: Relevant maintenance, diagnostic and quality-control information.
- Specific events: Tell counsel about anything you recall before or during testing. A medical diagnosis or possible exposure alone does not establish that a result was inaccurate.
An attorney may consult a qualified expert when the records raise a technical issue. A suspected problem must be connected to this test; neither a diagnosis nor an imperfect procedure guarantees exclusion.
Why throwing out a test may not end the case
Section 169A.20 includes both an under-the-influence offense and an alcohol-concentration offense. Observations, driving behavior, recordings and other admissible evidence may remain relevant even if a test is excluded.
The concentration provision also covers a qualifying measurement within two hours of driving, operating or physical control. A claim that the concentration was lower at the exact moment of driving is not automatically a defense to that provision. The charge, timing and evidence must be evaluated together.
Depending on the issue, counsel may challenge admissibility or the weight of the evidence. Dismissal, reduction and acquittal are different outcomes; none can be promised from the existence of a testing concern. See our guide to issues that may support dismissal.
Do not overlook the separate license proceeding
A criminal case and an implied-consent license revocation are separate matters. Section 169A.53 generally allows a judicial-review petition within 60 days after receipt of a qualifying revocation or disqualification notice. Filing does not itself stop the revocation. Show counsel every notice promptly and confirm the deadline and filing requirements that apply to you.
Frequently asked questions
Does a medical condition automatically invalidate my test?
No. Explain the circumstances to counsel. The relevant question is whether evidence supports a problem with the actual result or procedure, potentially requiring expert analysis.
Should I try to recreate the test myself?
Preserve the original documents and your recollection instead. Home experiments are not a substitute for review of the instrument record and testing conditions. Our breathalyzer myths guide explains common misconceptions.
What should I bring to an initial review?
Bring your complaint or citation, test paperwork, license notices, court date and a brief timeline. Identify potential recordings or witnesses without altering or deleting evidence.
Does winning the criminal case automatically restore my license?
Do not assume so. Ask counsel to address both proceedings and the orders affecting your driving privileges. Read more about Minnesota DWI consequences.
Discuss your Minnesota DWI case
Contact Martine Law for help evaluating a DWI allegation in Minneapolis, St. Paul or surrounding Minnesota communities. Initial intake may be handled by a Director of Client Engagement (non-attorney). An attorney provides legal advice; ask about fees and the scope of representation.
General information, not advice about a particular case.
For an overview of the law and how we help, see our Minnesota DWI defense page.
