How To Win Your DUI Case

When preparing to fight a DUI charge, remember that you are presumed innocent and you have a right to question any evidence, testimony, test results, or assumptions that is presented by the prosecution against you.  This article will address some of the areas of the prosecution’s case against you that may be susceptible to attach.  This isn’t an all-inclusive list, but it will give you a good start in developing a strategy to identify reasonable doubt and win your DUI case.

  1. The Stop.  In order to pull you over, and officer must have reasonable suspicion that you are violating the law.  If the officer pulls you over based on your race or just a “hunch,” then you can file a Motion to Suppress.  In a nutshell, a Motion to Suppress is where you argue that the stop itself violated your Constitutional rights, and therefore the evidence against you should be thrown out.  Police officers are trained to document facts that lead to reasonable suspicion in their reports, so a Motion to Suppress is often an uphill battle, but sometimes officers make mistakes.  It’s worth looking at the stop because if you win on the Motion, that typically means victory on the whole DUI case.
  1. Challenge the BAC.  If your breath or blood tests show a blood alcohol level of .08 or higher, you will need to find a way to call into question the results of these tests.
  • Rising Blood Alcohol Defense – The key point here is that the .08 level has to be at the time you were driving.  The theory of this defense is that alcohol takes time to absorb into the blood stream.  The results of a breath or blood test could be higher during the test than during the operation of the vehicle, based on a variety of factors:
    • How much food has the person eaten?  (Food tends to slow down absorption)
    • Is the driver male or female? (A woman’s BAC may rise higher than a man’s)
  • Medical Problem Defense.  The key point here is whether you have a medical problem that would render the results inaccurate.
  • Do you have a medical condition such as asthma or emphysema that affects your lung capacity and ability to blow into a machine?
  • Question the reliability of the testing procedures.
  • Was the testing device calibrated and tested?
  • Was the person giving the test trained on the device?
  • How many times did you “blow” and were the results consistent or varied from each other?
  • Were you observed prior to the DUI?
  • Eating, drinking, smoking, vomiting, burping, etc. can all impact test results.


  1. Fight the Officer’s Observations and Field Sobriety Tests.
  • Speech impediment or Injury.  Do you have a speech impediment or other condition that could account for an officer’s observation of slurred speech?  Do you have a health condition that would prevent you from understanding or complying with the tests?
  • Weather conditions.  Was there wind, rain, snow, etc. that could have affected your ability to hear the officer’s instructions and comply with them?
  • Look at the National Highway Traffic Administration’s procedures to see whether the tests were administered properly.  If the officer did not properly conduct the tests, or if correct instructions were not given, then you can question the reliability of the conclusions drawn from the tests.

Your defense will be as specific as your facts, as each DUI case is unique, but this guide will assist you in finding and taking advantage of the weaknesses in the prosecution’s case against you.