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So You Blew on the Intoxilyzer? What does registering a .08 or above on the “Breathalyzer” mean for your legal defense. – Part 2

road with police tape.bmpDefending your Driving While Impaired charge with ingenuity means attacking the Intoxilyzer. The most effective way to attack the magic box is to hire your own attorney. The manufactures of the Intoxilyzer have a vested interest in selling the myth that they have created an instrument that never breaks down, never freezes up, and always produces a perfectly accurate reading. The reality is the intoxilyzer just like any computer has its problems.

The state will present the reading for the intoxilyzer by having the analyst who conducted the test testify. Typically an analyst is only qualified to testify about how the instrument is used to conduct the test. In other words he knows how to turn the instrument on, he knows how to enter the defendant’s name into the instrument using the keyboard, and he knows which button to push before asking to defendant to blow into the instrument. Despite their limited knowledge concerning the science behind the instrument, many analysts will testify about how the instrument works. This typically leads to disaster as the astute defense attorney will point out all the problems with the analyst’s testimony and entirely destroy the credibility of the state’s case with testimony from their own expert.

In North Carolina the Department of Health and Human Services has created regulations that lay out the foundation requirements for a breath test.These regulations state that every analyst must observe a defendant for 15 minutes before requesting that they submit to a test of their breath. The purpose of the observation period is to make sure the defendant does not eat or drink anything, vomit or burp in the fifteen minutes before a the test is requested. The observation period is typically a step in the process that many analysts virtually ignore. It is essential that an attorney defending a Driving While Impaired case request the video feed from the intoxilyzer room so that they will be able to see if the Officer requesting the test physically observed the defendant for fifteen minutes before the breath test.


The easiest and most dangerous mistake one can make when defending against a Driving While Impaired Prosecution is to accept everything the government asserts as being the truth. The zealous defense attorney will always question every aspect of the government’s case including the Intoxilyzer. Ask the right questions, make the analyst foolishly attempt to explain how the instrument works…Defendant with Ingenuity!

J. Bradley Smith is a criminal defense attorney in Charlotte who has helped countless clients who have faced DWI charges. If you or a friend find yourself in need of an attorney, please contact Arnold and Smith, PLLC at 704-370-2828.