Many folks stopped for DUI will be asked to submit to so roadside breath test prior to arrest. These roadside preliminary breath tests are a commonly used tool by law enforcement in a Torrance and many other cities in Los Angeles.
Problems arise however when the officer only obtains one sample of breath. All scientific studies reveal that duplicate sample are necessary to achieve a reliable result. For example, The recommended guidelines for the use of breath testing results in law reinforcement: two breaths, taken two to ten minutes apart after observation / alcohol-deprivation period of fifteen minutes [Dubowski, K.M., National Safety Council Committee on Alcohol and Other Drugs, October 1986. Duplicate Breath- Alcohol Testing, Am J Forensic Med Pathol., 1988, Sep; 9(3): 272.]
"The human variables on the accuracy of breath testing make duplicate testing mandatory. It is well known that "with only one subject sample, it is not possible to know, with a reasonable degree of certainty that a random error did not occur in the subject test. The rationale of requiring replicate analysis for any quantitative procedure is universally accepted." [Jones A.W., Precision, Accuracy and Relevance of Breath Alcohol Measurements, Modern Problems of Pharmacopsychiatry, Vol. 11, S. Krager, Basel, Switzerland 1976 pp 69-78]. The use of a breath test that only uses one sample should therefore be viewed with caution in a legal setting.
If your DUI case only involves one breath blow contact an attorney to discuss strategies to throw out the test completely.