Beating the Breathalyzer in a Chicago DUI

For several decades, the Breathalyzer has been front and center in the “war” against drinking and driving. Now, there is talk of lowering the Blood Alcohol Content threshold from .08 to .05. With such a small sample size (two or three drinks in most cases), accuracy will be even more important.

This accuracy is one of the biggest and darkest clouds that surround the Breathalyzer’s use. An experienced defense attorney can use the Breathalyzer’s flaws to essentially invalidate the test results, especially in borderline cases like a .09.

How Does the Breathalyzer Work?

The small, hand-held Breathalyzers that most Chicagoland police officers use all work in much the same way. Most of them have fuel cells that convert ethanol particles to electricity. The stronger the current is, the more ethanol particles there are, and therefore the higher the person’s breath alcohol content is.

That process sounds high tech, and police Breathalyzer techs often talk about these devices like they are a James Bond gadget that actually works. But the 1950s Drunk-O-Meter used basically the same technology. Once the jury understands that the Breathalyzer is basically like one of those I Love Lucy-era television sets, they are much less willing to accept its results at face value.

There is more. Vigilant readers noticed that the Breathalyzer measures breath alcohol level, and the law requires a blood alcohol reading. The Breathalyzer estimates blood alcohol content based on the breath alcohol readout. That extra step means that the results are even more uncertain. When a document is translated from one language to another, some words get lost in transition. Given the high burden of proof in criminal cases, a few words in a book, or a few hundredths of a point on the test, make a big difference.

Some Breathalyzer Flaws

These issues are not just theoretical shortcomings. There are some practical problems with the Breathalyzer, as well. Some of them include:

  • Mouth Alcohol: If the defendant burps even slightly, undigested alcohol from the stomach moves into the mouth and makes the results artificially high. Officers are supposed to continually monitor defendants for at least 15 minutes before the test, but they often turn their heads momentarily.
  • Calibration and Use: Today’s Breathalyzers are a little more sophisticated than they used to be. That means they are more accurate and also more difficult to maintain. A poor maintenance record usually means poor results, as well.
  • Acetone: Many people, most notably diabetics and smokers, have high acetone levels in their bodies. The Breathalyzer often reads acetone as ethanol. Once again, the result may be artificially high.

To drive these points home with the jury, many Chicago defense attorneys partner with degreed chemists or other expert witnesses. These individuals are often much more convincing than the police Breathalyzer technicians that prosecutors usually call to the stand.

If the Breathalyzer results are invalid, the defendant can still be found guilty of DUI. However, the prosecutor must use circumstantial evidence from the field tests. Many times, this evidence is quite weak, especially if the defendant consumed little alcohol. Moreover, without a BAC of .08 or above, the license suspension component of a DUI may not be as bad.

Contact Tenacious Lawyers

It is possible to successfully challenge the Breathalyzer results. For a confidential consultation with an experienced DUI attorney in Schaumburg, contact Glasgow & Olsson.

(image courtesy of Andrew Peloso)

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