If my breathalyzer two tests were 15% difference .109 and .094 in 5 min span then is that challengable in court and with the DMV

Asked about 1 year ago - Ignacio, CO

first DUI and officer was certified. I know there is a law in California if its .2 in difference then the tests are negated.

Attorney answers (5)

  1. Mark S. Solomon

    Contributor Level 15


    Lawyers agree

    Answered . More factors exist than just the result number of the breathalyzer. The officer's observations of you at the stop, existence of video of the officer's investigation, other witnesses, the officer's notes on your driving.

    Such a difference in the result number can be used both for you and against you. Best to talk to a lawyer who can review the discovery and give you an opinion based on all the facts.

    You can reach Mark Solomon at (720) 722-2050 for clarifications to any answers here. This is general informational... more
  2. Rhidian David Watson Orr

    Contributor Level 16


    Lawyers agree

    Answered . In Colorado, if the two tests are within .02 of one another, they are considered valid. The margin of error for the Intoxilyzer 9000 is .003. You results can be attacked based on weight and credibility, but will not automatically be thrown out because of the .015 variance between the two samples.

    You will need to hire an experienced DUI attorney to help formulate a defense strategy and the best tactics to attack the test results and the remaining evidence like roadside tests. You say you passed, but the officer will say you failed. He has to in order to have probable cause to invoke the express consent law.

    Your best bet is to make sure you have requested your hearing with the DMV and to then find an attorney you feel comfortable with. There are thousands upon thousands of license attorneys in Colorado. Problem is their are only a handful that really know the ins and outs of DUI law and the scientific and evidentiary nature of these cases. Do your homework and hire the best attorney you can afford.

    The Orr Law Firm, L.L.C - 303-818-2448 - Is Colorado's Premier DUI and Criminal Traffic Defense Law Firm. Rhidian... more
  3. Zachary J Weyher

    Contributor Level 4


    Lawyers agree


    Answered . The evidence used against you on a DUI charge will be all of the observed circumstances leading up to your arrest and breathalyzer. This includes your driving pattern, the stopping sequence once you are pulled over, the officers observations upon initial contact with you, your exiting the vehicle, your performance on the field sobriety tests, the preliminary breath test, and the actual chemical test.

    You can challenge all of those observations and a good lawyer will. Generally, and I practice in Utah, you are probably referring to the margin of error with respect to the breathalyzer, which here is a +/- .005, meaning that as a defendant you can argue the test may in fact be lower, the prosecution that your BAC may in fact have been higher at the time.

    the difference between .109 and .094 in a 5 minute span is certainly significant and worth challenging in both arenas. You will want all of the information on the machine itself: certifications, calibrations, test history...everything to demonstrate that the test performed on you was unreliable for every reason you can find and that in light of every indicia of reliability, including the disparity in the actual test results, such evidence should be given little, if any weight, in proving that you were impaired.

    Thanks and good luck.

  4. James C Forslund

    Contributor Level 19


    Lawyers agree

    Answered . The breath machine is programmed to invalidate the test if there is more than a .020 difference.

  5. Ethan Patrick Meaney


    Contributor Level 20


    Lawyer agrees

    Answered . In MN, as M. Forslund has stated, the DMT machine will automatically invalidate the results if both samples are not within .02 of each other. That is the standard in the scientific community.

    This is not intended as legal advice. No attorney / client relationship exists because of this response.

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