Backdoor Breath Testing 4: Legal Standards From Our Implied Consent Law and Standard Jury Instructions (Part III)

Posted On June 13, 2016 by Daniel Koewler

Last week was a very busy week for Ramsay Law Firm, but here's the final part in our recent trilogy of blog posts dealing with the legal standards that apply to uncertainty challenges to breath testing. The first two parts are here and here.

This post addresses some of the legal challenges the government raises when asked to explain why breath tests are so inaccurate. These are not challenges based on science â?? they are attempts to try and keep science out of the courtroom (which is troubling because they are often being raised by government scientists).

Margin of Error: The first attempt to keep science out of the courtroom is to try and call it irrelevant. This argument dates back several decades, when an old line of cases rejected attempts to apply a "margin of error| to breath tests. This argument looks good on its face, and falls apart completely when you think about it.

Back in the 80's, the argument was that there was a |theoretical margin of error| that applied to breath tests â?? and that some |fudge factor| needed to be added to every breath test. In effect, defense attorneys were attempting to re-write the Implied Consent statute; instead of proving an alcohol concentration of 0.10 (the legal limit in the 80's) the defense wanted the government to actually have to prove 0.11 (or some higher number, depending on what they wanted this |fudge factor| to be). The Court's rejected any theoretical or |alleged margin of error| on the legal ground that the statute simply wasn't written that way.

But pretending that |uncertainty of measurement| is somehow the same as |margin of error| only works if you're not paying attention to both the science and the law. We already explained how the law actually demands that the government provide evidence of exactly how uncertain its breath measurements are, but the science is even more straightforward.

In fact, the very organization that accredits the BCA goes to great lengths to explain that |margin of error| is a completely different concept than |uncertainty of measurement.| Here's the document so you can read about it yourself. Here is the biggest highlight:

Great care is taken to distinguish between the terms â??error' and â??uncertainty.' They are not synonyms, but represent completely different concepts; they should not be confused with one another or misused.

In layman's terms, |margin of error| was a cute theoretical concept, but |uncertainty of measurement| is premised on the 100% verifiable fact that |there is always uncertainty| and we can never know the true value of what we are measuring . . . and the 100% verifiable process that exists for determining exactly how uncertain every measurement actually is.

Minn. Stat. §634.16: The other interesting attempt to keep science out of the courtroom is the government claim that the Legislature requires us to keep science out of the courtroom.

Think about that for a minute . . .

Here's the statute this argument is based on: the relevant portion says, |the results of a breath test . . . . are admissible in evidence without antecedent expert testimony that a [breath test device] provides a trustworthy and reliable measure of the alcohol in the breath.|

Again, in layman's terms, this statute simply says that the government can put breath test results (scientific evidence) before a judge or a jury without first bringing in an expert to |lay the foundation| for the evidence. Basically, breath test results get fast tracked into court in a way that no other scientific evidence is allowed to be presented.

But arguing that this statute allows the government to avoid admitting how inaccurate their measurements are completely misses the point; the statute assumes that a breath test result is a |trustworthy and reliable measure of the alcohol in the breath,| but so does the concept of uncertainty of measurement. In fact, the VIM (cited to in previous posts) outright states that measurement uncertainty calculations are |based on the assumption that no mistakes have been made in performing the measurement.|

Measurement uncertainty only applies if we already assume that the measurement in question was trustworthy and reliable â?? it simply involves applying the final step and explaining how trustworthy and how reliable the measurement actually is.

So, where are we? We know the scientific community demands the reporting of measurement uncertainty, we know our statutes not only allow it but effectively demand it, and we know the State of Minnesota is not doing it.

Next up, we'll provide transcripts and commentary on how these challenges have been shaping up in court over the last few months.