The California Supreme Court ruled unanimously in July that drivers arrested for drunk driving may in some cases challenge the legitimacy of Breathalyzer tests.
Under California law, DUI suspects are generally charged with two violations: driving under the influence, which is determined through observation of behavior such as driving erratically or failing a field sobriety test like walking a line [23152 (a)]; and having a blood-alcohol level of .08 percent or higher [23152(b)].
Determination of blood-alcohol content can be done by Breathalyzer or blood test. Breathalyzer tests measure the alcohol level in a person's breath and then use a standard formula to convert that level to an estimate of blood alcohol content.
The problem is that the same formula is used for all people in all conditions. A person's weight, gender, and other physical characteristics, and even the weather conditions at the time of the test, can influence Breathalyzer results.
Because of this, the Court ruled that Breathalyzer results may still be used as evidence, but criminal defense lawyers will be able to challenge those results in defense of their clients, highlighting the importance of quality legal representation when fighting DUI cases.
"California Supreme Court allows challenges to Breathalyzer results," LA Times, July 10, 2009
"California Supreme Court says DUI breath test accuracy can be weighed," San Jose Mercury News, July 9, 2009
