In The News

Thursday, August 1, 2013

The Death of "Working Backwards" to Calculate a BAC in DUI - Another Reason Not to Take a Roadside PBT

By Michael Nichols
Categories: Michael J. Nichols, Drunk-Driving, OWI

One of the world's preeminent law enforcement authorities on alcohol and other drugs in the human body made a bold statement about using a breath or blood alcohol calculation to then work backwards and try to match a bodily alcohol content at the time of driving. AW Jones said recently "you shouldn't do it" in describing the practice of retrograde extrapolation. Retrograde Extrapolation is a method of using a breath or blood alcohol content measured at one point in time to then work backwards and try to calculate a person's bodily alcohol content at the time that he was driving.

Dr. Jones is a toxicologist/pharmacologist who works for a government laboratory in Sweden. He often is called upon by prosecutors to testify in cases. He has written several articles, chapters and treatises, including parts of a textbook relied upon by the Michigan State Police forensic lab.

"Dr. Jones is already on record as calling Retrograde Extrapolation a 'dubious practice' - he acknowledged that position during a recent speech in the United States and went even further to say 'you shouldn't do it," says Michigan OWI Attorney Mike Nichols. Nichols attended the speech at the summer session of the National College for DUI Defense in Boston Massachusetts.

Nichols adds: "the connection I make with that statement and politely declining to take a roadside portable breath test (PBT) is that the PBT is also dubious. The PBT is inadmissible as evidence. The fact that a person refuses a PBT is also inadmissible as evidence. Why take the PBT and only take the chance that an attorney, a witness or the judge slips up and allows the PBT into evidence? If there is no PBT and we can convince the government's witnesses to stop this retrograde extrapolation garbage then the only thing a jury can do is infer that the blood or breath estimate at the time of the test is the same as when the person was driving: an inference is not proof.

Nichols points out that Jones and many other scientists believe that many things affect the absorption and dissipation rate of alcohol throughout the body from person to person. "The less you give the government to try to convict you of a serious crime like drunk driving, the harder it is for the government to stain your good name with a conviction."

For the attorney who is committed to results, call the Nichols Law Firm lawyers at 517.432.9000 or e-mail Mike Nichols at mnichols@nicholslaw.net

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Peer Recognition

Mike Nichols is a national leader in drunk driving defense. He is a member of the Forensic Committee and Michigan delegate to the National College for DUI Defense. He is also a Sustaining Member of the College. Nichols is also a founding member of the Michigan Association of OWI Attorneys; a member of the American Chemical Society; an associate member of he American Academy of Forensic Science, Adjunct Professor of Forensic Evidence in Criminal Law and OWI Law and Practice at Cooley Law School. He is also author of the West OWI Practice book and several chapters in other books on science and the law.

Mike Nichols is recognized by his peers in Michigan as a “SuperLawyer” in DUI/Criminal Defense. Nichols has also been asked to speak at conferences by groups such as the NCDD; Various Bar Associations in other states.