San Diego, CA- A recent decision by the California Supreme Court ruled that defendants in DUI cases cannot bring forth experts to challenge the soundness of breathalyzer tests and upheld the DUI conviction of a San Diego man.

In their opinion, the justices wrote that breathalyzers are “scientifically reliable” tests which cannot be challenged in court, but said a defendant can challenge whether a device is properly calibrated in their trial.

The opinion written by Chief Justice Tani Cantil-Sakauye, asserted “California has in essence determined that all models meeting the federal standards produce sufficiently reliable results for purposes of California’s statutes relating to alcohol-concentration limits.”

The case centered around the 2007 arrest of Terry Vangelder who was stopped by police when they caught him driving at 125 mph on Route 163. Police suspected Vangleder, who admitted to have two or three glasses of wine, was intoxicated and asked him to submit to a breathalyzer test, according to UT San Diego.

In two tests conducted at the scene on a hand held breathalyzer device, Vangelder registered a .0195 and a .086 blood alcohol concentration. However at the police station a different breathalyzer device registered his BAC at .08, the minimum legal limit for the state.

As part of his defense, Vangelder and his DUI attorney, presented expert witness testimony which challenged the scientific reliability of breathalyzers.

In his testimony, Dr. Michael P. Hlastala, Vangelder’s expert witness said breathalyzers were “inherently inaccurate” because the test worked on the theory that alcohol concentration on the breath is directly related to the alcohol concentration in the blood. Hlastala also said in his testimony that psychological factors can affect the results of a breathalyzer even when the device was working properly.

The jury only a heard part of Dr. Hlastala’s testimony since the trial court ruled that most of it was inadmissible in court. They however allowed him to present testimony to the jury that challenged the reliability of the particular device used to measure Vangelder’s BAC and was allowed to testify that the results could have been contaminated by “mouth alcohol” which dissipates before making it into the bloodstream.

The trial jury convicted Vangelder of misdemeanor DUI, but the 4th Circuit Appeals court later overturned his guilty verdict on the grounds that the court wrongfully excluded Dr. Hlastala’s testimony and ordered a new trial. San Diego city attorney Jan Goldsmith then appealed to a higher court.

The Supreme Court disagreed with the appeals court decision and upheld Vanglder’s DUI conviction, but his attorney plans on taking the case to federal court.

Most DUI cases are pleaded out before they make it to a courtroom, but the decision the Supreme  Court decision could affect what expert testimony is considered admissible in future DUI court cases and could make it more difficult for DUI attorneys to challenge the reliability of breathalyzers in other cases.