We Work To Prevent DUI Convictions Based On Inaccurate Blood and Breath Test Evidence

At Rosenstein Law Group, we represent clients in all types of DUI/DWI cases in Fountain Hills and throughout the Phoenix area and across Arizona. Attorney Craig Rosenstein is a Board-Certified DUI Defense attorney – one of only a handful in the entire state. We know how to examine blood and breath evidence and find the flaws that could provide the keys to your freedom. If you have been charged with drunk driving based on the results of a blood or breath test, you should contact an attorney immediately.

Understanding the Breath Test

One of the most common ways to measure and assess a subject’s blood alcohol concentration is through the breath test. This is done by the subject giving a sample of their breath into a machine that determines how much alcohol is on their breath. Per Title 13, Arizona Department of Public Safety: R13-10-103, there are very few devices that are permitted to be used and they must meet rigorous standards of performance.

For example, the device must meet a very specific accuracy limit: less than ± 0.005 grams per 210 liters or ± 5 percent. There are also specific devices that have been approved by the Director for use in the field. Those that are listed by the National Highway Traffic Safety Administration on their Conforming Products List of Evidential Breath Alcohol Measurement Devices fall under this category.

Other approved devices and models include:

  • Intoxilyzer Model 5000
  • Intoxilyzer Model 5000EN
  • Intoxilyzer Model 8000
  • RBT AZ (Alco Sensor AZ / RBT AZ)

For a breath test to be properly administered the arresting officer must determine that the subject fits all criteria and is a good candidate; for example, they must be physically and mentally capable of taking the test. While preparing, the officer must observe the subject for at least 20 minutes to ensure that the subject still meets all criteria; this means they cannot be burping, hiccupping, vomiting or otherwise doing something that would affect the integrity and accuracy of the test.

After 20 minutes, should the subject be suitable, the officer may administer the test. Following – at least 5 minutes after the first test, but no more than 10 minutes later – a test must be administered again. The results of the tests must be within .020 BAC of each other to be considered accurate. If not, results are considered to be “out of range.”

Although considered to be one of the most accurate ways of testing a subject’s blood alcohol concentration, there are many problems that have been noted with the test. For example, the machines are notorious for being delicate and requiring almost constant calibration. If they are not receiving this, there is no way to know for sure that they are still operating correctly. Law dictates how long a machine can go between calibrations; however, if the machine went too long, the results would need to be thrown out. Similarly, there are other extenuating circumstances that can affect validity; if the subject was throwing up, still had alcohol present in their mouth, was a diabetic or simply had a bio-chemistry that caused the machine to overstate the result it could potentially affect the accuracy of the test.

How Blood Test Evidence Can be Inaccurate

Another common form of testing a subject’s blood alcohol concentration is the blood test. This is generally viewed as more scientific and accurate than the breath test, but still, there are noted discrepancies. Unlike breath tests, the blood test cannot be performed roadside; instead, the subject must be taken to an approved facility where the blood will be drawn by a properly trained technician. While this appears to be relatively straightforward, there are still circumstances that can affect the test. Since the officers went to a 5-day course, they often claim to be qualified.

For example, should the technician drawing the blood use an expired NIK kit, the entire test would be false. Similarly, if the technician swabs the draw spot with a solution that contains alcohol, it would affect the alcohol detected in the sample and therefore the entire result of the test. Similarly, during storage, the blood is to be mixed with anticoagulants and preservatives; if this mixture is off or if the proper amount is not mixed in, the blood could essentially go “bad.” Other situations that can occur include the lab technicians mixing in too much salt, or the test being done on the blood serum or plasma instead of the whole blood.

There are many serious penalties that you could face for conviction of a DUI charge, do not hesitate to contact our firm today to discuss your case and how our firm will be able to help you.

Call us today at 480-248-7666 for a free case evaluation.


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