DUI Expert Testimony on BAC

By Robert W. Current, Ph.D., JD

Summary of: https://www.currentpllc.com/journal/JoCL-V2I1A2.pdf, with citations omitted.

Introduction

In the 1970s the US National Highway Traffic Safety Administration began investigating the level of alcohol in blood that would impair driving a motor vehicle, and 0.10 percent blood alcohol content (BAC) became the legal limit. Over time, states have written laws with lower limit; reaching as low as 0.01 percent BAC now in some cases. But how accurate are they actually measuring the alcohol content of blood?

Two Categories of Instruments Used

The vast majority of evidence presented to show alcohol intoxication relies on one of two types of measurements, breath or blood. Samples are collected from breath for immediate analysis, or samples are collected from blood for a more accurate analysis that requires more time. But are they giving a number that is useful to a court of law, that the prosecution can support with thier expert?

The Breathalyzer

The standard in many police stations today is an instrument based in the principles of infrared spectroscopy, but fuel cell technology has been growing increasingly accepted. The presumption that the BAC measurement from any of these instruments is accurate relies on both the instruments precision and accuracy in assigning the correct value to its measurement of the alcohol in the breath, and the correlation between the level of alcohol in the breath and what would have been in the blood.

The Blood Test

Although the test is more invasive than analysis of breath, testing BAC by headspace gas chromatography is considered the gold standard today. Blood is analyzed by headspace gas chromatography, after proper sample storage and sample preparation. The presumption that this measurement is accurate relies on both the instruments precision and accuracy in assigning the correct value to its measurement of the alcohol in the headspace above the sample, and the correlation between the level of alcohol in the headspace of the sample vial after sample preparation and what would have been in the blood.

The Daubert Standard

Most states have adopted rules of evidence similar to the federal rules regarding expert testimony, and apply the Daubert standard when viewing BAC evidence. Generally speaking, the rules of evidence require that an expert have knowledge, skill, experience, training, or education if they are to testify in the form of an opinion, and that “the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue; (b) the testimony is based on sufficient facts or data; (c) the testimony is the product of reliable principles and methods; and (d) the expert has reliably applied the principles and methods to the facts of the case.” In applying this rule, the trial judge must ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable. The four factors to be reviewed when applying this rule are: 1) whether the theory or technique can be supported or has been tested, 2) whether the theory or technique has been subject to peer review, 3) whether the error rate is known and standards exist controlling the operation of the technique, and 4) whether the theory or technique has gained general acceptance.

Meeting the Daubert Standard for Expert Witnesses

As an expert witness, I have meet the requirements under the rules and standards, as that I have the knowledge, skill, experience, training, and education to address the theory and techniques used for BAC measurements, and understand how the peer-reviewed scientific literature applies, as well as a firm undemanding of the sources, types, and unique qualities found in the error rates of the instruments used in BAC analysis.

I have a doctorate degree in analytical chemistry, graduated from law school, a strong understanding of science, and I have spent over a decade of my career involved with use of similar equipment in laboratories. I have developed and designed of modern scientific equipment that uses the same principles as used for BAC testing, while working in scientific instrumentation companies providing custom equipment designs for the pharmaceutical and petrochemical industries.

I began my academic studies of science and engineering in the late 1980s, enrolling in a wide range of college courses from aerospace engineering and computer programming to physiology, zoology, and genetics. I have served as the representative for the Med-Dent Society while attending the California State Polytechnical University in Pomona, and went on to work on molecular modeling research of un-natural 2’-5’ DNA strands at the University of California, in Riverside, where I obtained my Bachelor’s Degree in Chemistry.

During my doctorate work, I won several awards for my research, including a University Invasion Grant from Parker Hannifin Corporation in 1994 for research in supercritical fluid extractions, a North Dakota Academy of Science Research Award in 1997 for designing instrumentation to study soil contamination, and two NASA Space Studies Grants in 1998 and 1999.

I began working in the area of equipment design with fiber optic applications to spectroscopy methods in 1995. By 1996, I had designed, built, and tested UV, Visible, Near IR, and IR spectroscopy, for applications in food analysis and environmental testing with research presented at national and international scientific conferences.

In 1997 I had started to design chromatography equipment, and my research was presented at the most attended annual conference on analytical chemistry and applied spectroscopy in the world. That year, I also appeared as the first author in a scientific publication about an instrument I had designed and built to use supercritical fluids for environmental contamination testing.

During the period from 1998 to 2001 I was regularly presenting my research at scientific conferences, with designs that made breakthroughs in both speed and sensitivity, leading developments in the areas of sample preparation, improved instrument design, and publish in premier scientific journals in chemical analysis, environmental testing, and other areas of science.

I began teaching in chemistry laboratories during my time in graduate school at the University of North Dakota, and I have been certified to teach Chemistry at Pima Community College in Tucson, Arizona since 2007.

Analysis of Data in Cases

There are a number of ways that blood alcohol results may not meet the Daubert standard that often go unchallenged. The standardization of the calibrations, as well as the client’s blood alcohol results, must be considered in terms of both accuracy and precision.

During discovery, often the State will provide minimal data regarding the BAC of the defendant. There may be gaps in the information that are necessary to confirm the quality of the data presented, such as the ability to verify the calibrations of the equipment used, documentation about the procedure in place and if it was correctly followed, as well as errors that can be uncovered during a statistical analysis of both the defendant's test itself, calibration runs, and other data from the same instrument that day and at other points in time.

The data used against your client may not meet the Daubert standard. I meet the Daubert standard, and not only am qualified to identify and comment on the errors in data the State presents, I also have the teaching experience to explain it clearly to a judge and a jury. Contact me at Current Law for a consultation on anything from a basic review of the case and data, to testimony at trial.