What You Need To Know > DUI > Doesn't the test mean I'm guilty?
The chemical tests for blood or breath alcohol levels are fraught with problems. Many people clearly have had only one or two drinks, yet their "test" shows an alcohol level well above .08. The technical and scientific issues with chemical testing make DUI cases some of the most interesting and challenging cases in the law. Whenever machines purport to tell you what was going on in a person's body at some time prior to the time of the test, the risks of error multiply.
Generally, there are two categories of error: First, issues with the machine, and second, issues with human biology. To take breath testing as an example, while there are many potential problems on the machine side--from design flaws to maintenance issues--the most glaring problem is this: human bodies are all different, short/tall, big/small, male/female, but the machine doesn't make adjustments. The same set of bioengineering assumptions are imposed on every test. I have worked with some of the best experts in the country to understand the strengths and weaknesses of each test. And if I've learned one thing it is this: every case is different, and each one turns on the details of its own facts.
So to answer the question: No, the test does not mean you're guilty; it may turn out to be the strongest piece of evidence for the defense!
Last updated on July 8, 2009 by Jim Dunn