Case Explained: Minnesota needs independent oversight of forensic labs – Legal Perspective

A recent impaired-driving case in Minnesota revealed a troubling problem inside the Midwest Regional Forensic Laboratory: an expired calibrator was used during blood-alcohol testing. Calibrators are the reference standards used to verify that scientific instruments are producing accurate results. The issue was not discovered through routine oversight. It surfaced only after an outside expert demanded additional records.

Unfortunately, this is not an isolated problem.

In 2025, a Minnesota veteran found himself fighting a DWI case over a urine alcohol result that had been rounded upward by laboratory software. His measured value was 0.0799, below the legal threshold. But when the laboratory converted the result into statutory units, the software rounded the value up to 0.08.

That tiny change forced him to challenge the result in court. The laboratory defended its rounding practice, but the judge ultimately threw out the test.

These examples may sound like minor technical details. But in forensic science, they are not. Small technical decisions about rounding, reference standards and quality controls can determine how scientific evidence is interpreted in court. It can mean the difference between conviction and acquittal.

Minnesota has seen this pattern before.

In 2010, the Tri-County Regional Forensic Laboratory reported urine alcohol concentrations incorrectly because results were not converted into the statutory units required by Minnesota law. This caused alcohol concentrations to be reported about 50% higher than they should have been.

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In 2011, the state also experienced the Intoxilyzer 5000 source-code controversy, in which a known software patch was not installed for years despite the defect having been identified. This error led to certain valid breath samples being rejected, exposing drivers to harsher refusal penalties.

In 2012, serious problems were uncovered at the St. Paul Police crime laboratory after a court challenge revealed that drug analysts were operating without written standard operating procedures or properly validated testing methods. Independent reviewers later found major deficiencies in documentation, quality assurance practices and analytical procedures. Drug testing at the lab was eventually suspended while the problems were investigated.

Minnesota spent roughly $1.7 million on the DataMaster DMT, a breath-testing machine that used two analytical technologies. Yet one of those analytical components, the fuel cell, was turned off despite being promoted as an important safeguard.

And just last fall, problems involving dry-gas reference materials used to check breath-testing instruments forced prosecutors to dismiss or reevaluate dozens of cases across the state.

These events share a common theme: the problems were discovered only through defense discovery motions and independent expert scrutiny. 

We are at a time when Minnesotans are increasingly concerned about how government funds are used. Forensic laboratories operate with public funding and play a critical role in the criminal justice system. Yet Minnesota still lacks an independent body responsible for investigating forensic errors, reviewing scientific practices and ensuring transparency before problems occur.

Other states have recognized this gap and created independent forensic oversight bodies.

At least 18 states now have forensic science oversight boards that review laboratories and investigate scientific failures. These include states across the country, from Texas and Massachusetts to New York, Virginia, Washington, and Illinois. The movement has grown large enough that, in 2025, the National Association of Forensic Science Boards was founded. 

Minnesota taxpayers fund forensic laboratories because their work is essential to the justice system. When errors occur, the public deserves to know about them quickly and transparently. Oversight is not about blaming scientists or police agencies. It is about ensuring that publicly funded laboratories meet the highest scientific standards.

To be clear, most forensic scientists in Minnesota work diligently and professionally. The issue is a system that lacks independent oversight and transparency when problems arise.

Minnesota should establish an independent forensic science oversight board with the authority to investigate laboratory errors, review scientific practices, and require public reporting of quality assurance failures. Such a body should operate independently from law enforcement and include independent scientists, legal experts and public representatives.

Forensic science measurements carry enormous weight in legal cases. When a laboratory reports a number, judges and juries often assume it is reliable.

That level of trust demands transparency and oversight.

Minnesota should not wait for the next laboratory mistake to be uncovered. The state should act now to ensure that forensic science operates with the accountability, openness and scientific rigor that Minnesotans deserve.

Aaron Olson is a forensic toxicology consultant and former forensic scientist with the Minnesota Bureau of Criminal Apprehension. Daniel Koewler is a partner at Ramsay Law Firm in Roseville and a Minnesota attorney who focuses on DWI defense.

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