Admission of Blood Results Uncertain in Michigan

A Mason County judge has ruled that a failure to report the uncertainty of its blood test measurements by the Michigan State Police Crime Laboratory1 (MSP Crime Lab) is fatal to the admissibility of the reported result. This ruling is likely to send tremors around the state as prosecutors and forensic scientists scramble for ways to overcome the judge’s ruling. As it stands, this ruling may have relevance in what happens to each of the more than 10,000-plus blood alcohol tests performed in the Lansing MSP Crime Lab each year.

The case,2 handled by Michigan lawyer Mike Nichols, involved a man who was arrested for felony drunk driving. The Lansing MSP Crime Lab Toxicology Report suggested that the blood alcohol level for this driver, Mr. Jeffrey Jabrocki, was .29, or nearly four times the legal limit. At the preliminary hearing the prosecutor sought admission of this result and Mr. Jabrocki’s attorney responded that the prosecutor had failed to lay a proper foundation, citing the case of Daubert v. Merrell Dow Pharmaceuticals.3

The Daubert4 case suggests several factors that are commonly pertinent to the admission of scientific evidence. These include:

  1. whether the theories and techniques employed by the scientific expert have been tested;
  2. whether they have been subjected to peer review and publication;
  3. whether the techniques employed by the expert have a known error rate;
  4. whether they are subject to standards governing their application; and
  5. whether the theories and techniques employed by the expert enjoy widespread acceptance.

The Jabrocki case focused primarily on item number three, which was restated: does the .29 blood test result reported by the MSP Crime Lab have a "known error rate?" The suggested conclusion was that if it does not, then the necessary Daubert5 foundation cannot be satisfied. What was novel about this approach is that it was the first successful Michigan challenge to dovetail the Daubert6 criteria with the science of measurement known as "Metrology."

Metrology includes all theoretical and practical aspects of measurement, whatever the measurement uncertainty and field of application.7 Metrology embraces error rate in all of its incarnations and requires that all possible error be accounted for, tracked and reported. This is because every measurement, including any blood test result derived at the MSP Crime Lab, "has an uncertainty associated with it, resulting from errors arising in the various stages of sampling and analysis and from imperfect knowledge of factors affecting the result. For measurements to be of practical value it is necessary to have some knowledge of their reliability or uncertainty."8

Thus, the question raised in the Jabrocki case relative to the blood test result reported by the Lansing MSP Crime Lab is not one of just academic importance, nor is it simply an idea possessed by the abstract scientific mind. Metrology, and the preparation of its attendant "uncertainly budget," it quite literally a requirement of accreditation. In other words, in order for the MSP Crime Lab to demonstrate quality assurance and to maintain its accreditation it is mandatory for the lab to determine and report uncertainty. This means that, "[T]he laboratory shall have quality control procedures for monitoring the validity of tests and calibrations undertaken. The resulting data shall be recorded in such a way that trends are detectable and, where practicable, statistical techniques shall be applied to the reviewing of the results.9

Furthermore, [T]he American Society of Crime Laboratory Directors (ASCLD) states that participation in an accreditation program (requiring compliance with ISO 17025) is, "important to demonstrate to the public and to users of laboratory services a laboratory’s concern for and commitment to quality." ASCLD also states that "[L]aboratory managers should support peer certification programs which promote professionalism and provide objective standards that help judge the quality of an employee’s work." Clearly, the forensic science community and the larger legal community expect forensic science organizations to look to certification and accreditation bodies for guidance.10

It should be noted that these standards are not new. In early 2009 the United States National Academy of Sciences released a long-awaited report11 in which it made a number of recommendations for strengthening the forensic science system in the United States.

Recommendation 3 in this report in part called for "quantifiable measures of the reliability and accuracy of forensic analysis." Likewise, ISO accreditation criteria, developed for testing laboratories worldwide, require that testing laboratories provide statements of measurement uncertainty in a form useful to their customers. Perhaps most important is a growing recognition that uncertainty of measurement is needed for proper interpretation of laboratory results, especially when those results are close to a legal threshold.12

Returning now to the blood test in the Jabrocki case, although the .29 seems quite high, it was argued that without a "known error rate" it is impossible to give this result any legitimate legal meaning. This is because ". . . methods for measuring the level of blood alcohol in an individual . . . can do so only within a confidence interval of possible values" so that such "measured results need to be reported, along with a confidence interval that has a high probability of containing the true blood-alcohol level . . . "13

As has been shown, this argument was based on the science of metrology where it is understood that, "knowledge of the uncertainty associated with measurement results is essential to the interpretation of the results. Without quantitative assessments of uncertainty, it is impossible to decide whether observed differences between results reflect more than experimental variability, whether test items comply with specifications, or whether laws based on limits have been broken. Without information on uncertainty, there is a risk of misinterpretation of results. Incorrect decisions taken on such a basis may result in unnecessary expenditure in industry, incorrect prosecution in law, or adverse health or social consequences."14

What is particularly interesting about this case and the testimony received is that the director of the Michigan State Police Toxicology Lab15, Dr. Felix Adatsi, testified that he was aware of the ISO 17025 requirement to, "construct an error budget that accounted for all elements of systematic error, but that such efforts would be time consuming and difficult."

What’s more, Dr. Adatsi knew that his lab was warned back in 2007 that an error budget was necessary "by the next audit." The Michigan State Police Toxicology Lab simply resisted or refused to perform such time consuming and difficult work. Their hope was that a different option would become available, allowing them the ability to forgo the preparation of any uncertainty budget. This procrastination came despite the fact that ASCLAD has long required an uncertainty budget to demonstrate a commitment to and concern with quality.

So there it lies. The otherwise punctilious Michigan State Police Toxicology Lab carefully utilizing forensic scientists following detailed protocol performing tests on the gas chromatography "guilty machines," producing what are widely viewed as "unassailable" blood test results, has the temerity to claim that it’s just too much trouble to otherwise comply with their own standards or those of sound science. Yet their ironic failure to do so in this context, that is, their failure to determine exactly how much uncertainly really exists in the results they report, actually renders the results scientifically meaningless. All that hard work wasted.

After pondering all this, a law-enforcement-biased cynic may rhetorically ask: the system historically produces a sufficient number of guilty pleas and guilty verdicts, so why is there any need for change? Why indeed. As Judge Wadel points out in his opinion, if Mr. Jabrocki’s blood was tested 100 times, each result would likely be different. This is because, "for even the most carefully performed measurement, the value of a thing being measured can never be known exactly; all that can ever be given is an estimated value.16

On the other hand, a defense-biased cynic may ask: what was Mr. Jabrocki’s true blood alcohol level at the time he was driving? The scientifically sincere answer is that without an uncertainty budget it’s not possible to know. This means that it is also not possible for defense counsel to properly advise his client or for a jury to properly weigh this evidence. All of this is true even with a blood alcohol report that ostensibly places his blood alcohol level at nearly .30.

Which all leads to an encompassing and entirely non-cynical but tremendously important question: did Mr. Jabrocki have an unlawful bodily alcohol level at the time he drove his car? Due to the abject failure of the Michigan crime lab to report uncertainty, we may never know.