Attacking Breath Test Evidence of DUI Guilt in Arizona
If you're facing an Arizona drunk driving charge that specifies a certain blood alcohol concentration (BAC) as necessary to support a finding of guilt, it's essential that your DUI defense lawyer knows how to evaluate and challenge the breath test results on any of several grounds. To learn how we defend DUI cases by attacking the toxicology evidence, contact The Gillespie Law Firm in Phoenix for a free consultation.
First, it's essential to understand the difference between the Intoxilyzer test that measures your BAC based on a breath sample and the preliminary breath test (PBT) that an investigating officer uses in the field to determine whether you have been drinking. Only the Intoxilyzer evidence can be used against you in court, and you have no right to refuse the test. The PBT result can't stand as evidence against you, however, and you can actually refuse to take the PBT test. The officer might still arrest you and get a breath or blood sample from you later, however.
One of our first lines of DUI investigation concerns the breath analysis device itself. The Arizona Department of Health Services requires that each device be calibrated to a 10 percent margin of error every 31 days, and the Department performs its own evaluation of each device every 90 days. If we find that the accuracy of the device that measured your BAC is subject to question for lack of maintenance or failed inspection, our lawyers can often show that your breath test evidence should be disregarded.
Our DUI attorneys also work with forensic toxicologists to consider the following factors that could bear on the accuracy of your breath test and the integrity of the results:
- The particular device's margin of error
- Mouth alcohol from mints, lip balm or other artificial inflators
- Body alcohol generated through certain liver, kidney or gastric conditions
- Power source or radio interference with the Intoxilyzer's performance
- Operator error due to inadequate training, missing instruction manuals or other circumstances
Focusing on the details of a failed breath test can be especially important in marginal cases, such as where you blew a .09 or a .16. Showing that the test could just as easily have shown a BAC a couple of points lower can save you from a conviction of DWI per se or extreme DWI.
Failed a DUI Breath Test? Call 888-613-5322 in Phoenix
Find out more about our ability to work effectively with experts to find the weaknesses in DUI breath test evidence. Contact an attorney at The Gillespie Law Firm in Phoenix for a free consultation.
