Breath & Blood Tests
Are Blood Tests Always Accurate?
Despite their scientific nature, breath and blood tests do not necessarily provide conclusive evidence regarding your blood alcohol concentration (BAC). Several factors may affect the accuracy of the results obtained in your case and an experienced Tempe DUI lawyer from the Law Offices of Trent R. Buckallew, PC has the experience and knowledge regarding both blood and breath results. A breath test may be administered incorrectly, the device may be calibrated incorrectly, or equipment errors may result in an erroneous reading. A blood test may not be administered in a medically approved manner and a mishandled sample may be compromised and not valid for testing. Testing can be done incorrectly, also resulting in false results. It is critical to obtain legal counsel who is adept at understanding the science behind the evidence in DUI cases.
There are many complex factors that may operate to undermine the validity of breath test results in a DUI case. Some of the factors that can undermine the reliability and accuracy of breath analysis machines include the following:
- Radio frequency interference (radio frequencies in the air, from cell phones, and police radios, effecting the actual functioning of the machine during the test)
- Health conditions
- Breathing patterns of the person being tested
- Mouth alcohol (residual alcohol in the mouth causing artificially inflated results)
- Stress of the person being tested
- Contaminated equipment
This is only a general overview of the complex issues of concern when investigating a breath based DUI case. You should seek and retain a competent DUI attorney to assist you in determining which, if any, of the potential error sources in breath testing may be applicable to your individual case. An experienced DUI attorney will also be able to discuss the admissibility of breath evidence, and under what conditions this evidence may be admissible. Thus, it is important to retain an attorney who understands both the complexities of the science behind breath testing as well as the manner in which it may be admissible during a DUI trial.
Blood based DUI cases present some of the most difficult challenges from a defense perspective. This is because blood testing is generally considered a superior method of determining alcohol concentration within the body when compared against breath testing. However, even blood testing has its potential error sources. Some of the procedures that should be reviewed in order to identify potential error sources include:
- What type of swab was used to prep the skin at the time of the blood draw? Alcohol-based or non-alcohol based disinfectant swab?
- Was the sample properly packaged? Stored?
- Where / how was the sample stored?
- Who had access to the sample?
- Did the criminalist photograph the condition of the evidence?
- How many total samples were in the batch run? Where there any errors involving any of the other samples?
- Was the machine properly calibrated?
This is only a partial list of the many areas that should be reviewed in conducting a proper investigation into the reliability and accuracy of any blood-based alcohol test. It is important to seek out and retain an attorney who has the experience in both DUI defense as well as an in depth understanding of the forensic evidence inherent in DUI cases in order to identify any potential weaknesses which may serve to undermine the State’s case.
Not only is Mr. Buckallew well versed in criminal law, having undertaken an academic concentration in criminal litigation during law school, he has received his Master of Forensic Science (M.F.S.) degree, and is also a member in the American Academy of Forensic Science. Having an attorney trained in both the law, and the forensic sciences, is critical given the growing importance of forensic science in criminal litigation. Whether it is a misdemeanor or felony DUI, forensic science will likely play a significant role in your case. Maintaining a statewide practice, Mr. Buckallew can represent individuals in any court in the State of Arizona, including City Courts, Municipal Courts, Justice Courts and Superior Courts and he has nearly 20 years of experience in the practice of criminal and DUI defense.
In any DUI case, breath and blood tests should be evaluated by an experienced attorney and a complete investigation of the case should be conducted. For legal assistance and a free case evaluation, contact a Tempe DUI attorney.