Big Surprise: Breathalyzers are Inaccurate

Posted by Jon Ibanez on November 7th, 2019

I’ve been saying and writing about it for years; breathalyzers are inaccurate. Now, The New York Times, in a bombshell report confirmed exactly that.

According to the report, “The Times interviewed more than 100 lawyers, scientists, executives and police officers and reviewed tens of thousands of pages of court records, corporate filings, confidential emails and contracts. Together, they reveal the depth of a nationwide problem that has attracted only sporadic attention.”

With so much at stake, including jail, you’d think that there would be more than mere “sporadic attention.”

Yet, the report found numerous inconsistencies with maintenance procedures of breathalyzer machines, inconsistencies within the machines themselves, and an over reliance on inaccurate data produced by breathalyzers.

In Colorado, for example, police had continued using a chemical solution that had long been expired when prepping the machines. The expired solutions caused inaccurate results. In another example, a former manager created his own chemical solution inconsistent with the standard chemicals used in the solution.  In some instances, there were no standards on how to prepare and operate the machines.

The report also found that the manufacturing process of the breathalyzer machines also create inaccuracies. For example, testing revealed that some machines produced a result even though the software programed into the machine occurred. Some tests revealed that accuracy of reading was affected by external factors such as the temperature of a person’s breath, whether they’ve consumed breath mints, or whether they’ve recently brushed their teeth, to name a few.

Despite the known inaccuracies, breathalyzer machines continue to often be the deciding factor in a DUI conviction.

In 2013, the California Supreme Court held that, although breathalyzers are generally inaccurate, scientific evidence challenging the accuracy of breathalyzers in California is not admissible as evidence in DUI trials.

The holding comes from the 2007 DUI stop of Terry Vangelder. Vangelder was stopped for speeding in San Diego. Although having admitted to consuming some alcohol, Vangelder passed field sobriety tests. Vangelder then agreed to a preliminary screening alcohol test (an optional roadside breathalyzer) which indicated that Vangelder’s blood alcohol content was 0.086 percent. Based on that, Vangelder was arrested and transported to the police station where he submitted to a chemical breath test (a required post-arrest breathalyzer). This breath test showed a blood alcohol content of 0.08 percent. Vangelder then submitted to a blood test which indicated that his blood alcohol content of 0.087 percent.

At trial, Vangelder called Dr. Michael Hlastala, a leading authority on the inaccuracies of breathalyzers.

“They are (inaccurate),” Dr. Hlastala testified before the trial judge. “And primarily because the basic assumption that all of the manufacturers have used is that the breath that [is] measured is directly related to water in the lungs, which is directly related to what’s in the blood. And in recent years, we’ve learned that, in fact, that’s not the case.”

The judge however, did not allow the testimony and Vangelder was found guilty. Vangelder appealed and the appellate court reversed the decision in 2011. San Diego City Attorney, Jan Goldsmith, then appealed the appellate court decision arguing that such testimony would undermine California’s a per se law making it illegal to drive 0.08 percent blood alcohol content or higher.

Unfortunately, the California Supreme Court sided with Goldsmith.

“[T]he 1990 amendment of the per se offense was specifically designed to obviate the need for conversion of breath results into blood results — and it rendered irrelevant and inadmissible defense expert testimony regarding partition ratio variability among different individuals or at different times for the same individual,” Chief Justice Tani Gorre Cantil-Sakauye wrote for the court. “Whether or not that part of expired breath accurately reflects the alcohol that is present only in the alveolar region of the lungs, the statutorily proscribed amount of alcohol in expired breath corresponds to the statutorily proscribed amount of alcohol in blood, as established by the per se statute.”

The Court went on to say that, “Although Dr. Hlastala may hold scientifically based reservations concerning these legislative conclusions, we must defer to and honor the legislature’s reasonable determinations made in the course of its efforts to protect the safety and welfare of the public.”

Simply put, the California Supreme Court is willfully ignoring scientific evidence simply because the legislature was well-intentioned.

Although drivers can no longer challenge the accuracy of breathalyzers in general, a driver who has been arrested for a California DUI can still challenge the accuracy of the specific breathalyzer machine used on them.

 

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