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The Four Most Common Breath Test Challenges


The Four Most Common Breath Test Challenges

1. Medical Conditions

2. Improper Testing Method by Officer

3. Source Code of Machine

4. Implied Consent and other Suppression Issues

Under Georgia law, a driver is in violation of our DUI statute when driving with an alcohol concentration in excess of the legal limit. These limits are 0.08g for a driver age 21 and over, 0.02g for a driver under the age of 21, and 0.04 for a commercial vehicle driver, in their commercial vehicle. Often times, a driver in violation of Georgia's per se (illegal alcohol concentration) statute will also be cited under Georgia's less safe DUI law. A less safe DUI case does not require any evidence of blood alcohol concentration, only proof that a driver was impaired by alcohol to the extent they were less safe to drive. A per se (illegal alcohol concentration) case is inherently tougher to fight, due to the scientific nature of the state's evidence; usually a breath test, or blood test. With this observation, we will outline the four most common breath test defense areas.

1. Driver's Medical Condition: Georgia's breath testing machine is the Intoxilyzer 5000, a machine adopted for use in Georgia and largely unchanged since 1994. The Intoxilyzer 5000 uses infrared technology to measure the level of alcohol in a sample of the subject's breath. While the machine's 15-year-old technology claims to have the ability to filter out other substances besides alcohol that could test positive in a DUI breath test, the area is ripe for attack. Medical conditions such as diabetes, ketosis (sometimes a dietary condition) and acid reflux can skew breath tests, rendering them inaccurate.

2. Failure of Arresting Officer to Follow Protocol: The GBI's Deptartment of Forensic Science has a protocol that must be followed when administering a breath test on the Intoxilyzer 5000. For example, the officer must keep a 20-minute observation period of the subject before administering any test. A failure to do so would allow mouth-alcohol, or residual alcohol to potentially contaminate a breath sample. Additionally, a testing facility must be clear of radio frequency interference (RFI). Even a cell phone in the testing area could be a potential cause of disruptive RFI, and could render a breath test unreliable.

3. Intoxilyzer 5000 Source Code: The Intoxilyzer 5000 machine functions with the help of a processor, similar to those found in many electronic devices. The breath testing machine contains a source code that instructs the various parts of the machine how to function in order to obtain a breath test reading. Recently, the machine's manufacturer, CMI, Inc., out of Owensboro, Kentucky has come under increasing pressure to turn over the source code of the breath testing machine. Defense attorneys argue that, as the exclusive provider of all breath testing machines used in the State of Georgia, CMI has the duty to make the machine's source code available to criminal defendants, who have due process and other Constitutional rights in defending their case.

4. Implied Consent & Suppression Issues: Defense attorneys utilize pretrial motions in an effort to suppress evidence. Many times, breath test results are the subject of these pretrial motions and if successful, your breath test could potentially be thrown out of the case against you. Under Georgia law, an officer who arrests a driver for DUI is obligated to read the implied consent notice immediately upon arrest and before having a driver submit to testing. The failure of the officer to do so could subject the state to having any later chemical test ruled inadmissible. Other common suppression issues include custody issues, probable cause issues, reasonable suspicion issues (why a driver was stopped) and Constitutional violations. Many times a motions hearing is held in advance of trial and after a defense attorney has reviewed the evidence, thus giving you and your attorney a chance to preview the state's case and devise a defense plan.

If you are defending a breath test, or per se case in Georgia, call or email me directly to discuss the facts of your case. Fighting breath tests in Georgia is a very scientific and difficult business. DUI trials on breath test require skill, experience and knowledge of all aspects of Georgia's breath testing laws. If you have been charged with DUI for blowing over the limit, I urge you to ask all lawyers you interview how many breath test trials they have had and what their success rate is, as well as their preferred methods for fighting the tests. Challenging scientific evidence in your case can be a time consuming and costly endeavor for both you and your lawyer, so you want an attorney on your side committed to bringing the truth about your breath test out. Write me at:, or call me directly at (404) 642-6333 if you have questions about your DUI defense. I will be happy to speak to you both on the phone and in-person at one of my Atlanta offices.

2012 Breath Test Jury Trial Reviews from Clients:

(1) I got a DUI 9 months ago. I was feeling really down, depressed and couldn't see light and end of the tunnel. I contacted several attorneys that all told me my case was hopeless, not winnable and that I was basically screwed. I was about to plead guilty until I called Evan. He set up a meeting immediately and even went out of his way to meet up with me and go over my case in person. He began working right away and guided me through the process. He personally kept in touch with me through phone calls, text messages and emails. Evan gave my family and I some much needed peace of mind. After months of no license and a lot of stress, I walked out of that court room with a not guilty verdict!! I can go get my license back today and I have a clean record!! Evan's skills in the court room were like that out of a movie. I was beyond impressed with how comfortable he was and how he could really connect with the jury. Evan kept it real, he's even called and kept in contact after the trial to check in on me. Evan Watson is hands down the best DUI lawyer around and a real stand up guy. I can't thank him enough for what he did for my family. Thank you Evan!!

(2) I hired Evan back in 2010 to represent me for a Douglas County GA.We had several calander calls over the past 2yrs.we were there together for each one.Evan noticed that the state did not have there main piece of evidence against me.We brought in an expert witness to show,that the officer performed the int.sobriety test incorrectly.and he lost his copy of the toxacology test.The day of trial.Evan stood his ground and showed that the state did not have a real case against me to the the jury.Evan showed the Jury why should not find meGuilty on the charges brought against me.The prosecutor tried real hard to prove his case and couldn't.The jury found me not guilty on both charges.of Dui.and Unsafe Driver.

Evan did a great job and theres not enough words to say thanks.

(3) Evan Watson did an excellent job with helping me with a rather lengthy process of a DUI case. The charges were initially filed Nov 2008 – DUI per se, DUI less safe, Reckless driving, and speeding. This case was held in one court for almost 2 years and then moved to another. For the first year of the case, Mr. Watson worked hard to just get a copy of the dashboard video. Once it was found, it turned out that there was no sound on the video. Mr. Watson was a great help to me and thorough in explaining my options. Due to the nature of my job (which requires travel), it was best to go to jury trial for the case. His strategy was to 1) show the shortcomings in the field sobriety test, 2) show lack of following all prescribed protocol of the officer, and 3) show the limitations of the breath analysis test and margins of error. He was able to present all 3 arguments in court and did an excellent job. On all three accounts, he was able to establish reasonable doubt in the minds of the jurors. This was all done without me even to have to spend thousands of dollars on expert witnesses. In the end, I was found innocent on both of the DUI charges and the reckless driving charge. In fact, since I had already taken the MADD impact panel and DUI (upon his initial advise), the judge even threw out the fine associated with the speeding ticket. As it turns out, I was actually his very first case that was assigned to him almost 4 years ago and he did an excellent job with the case. I could not be more satisfied. I would recommend his services to ANYONE.

For more DUI and other criminal defense reviews of partners Evan Watson and Peter Zeliff, see their profiles at

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