The California Supreme Court last Thursday entered a ruling allowing motorists accused of driving under the influence of alcohol (DUI) to question the reliability of the breathalyzer machinery used to secure convictions. The decision, however, leaves room for the conviction of drivers even when the machine is proved unreliable.
The high court recognized that a breath testing machine does not directly measure the alcohol content in a person's bloodstream. Rather, the device estimates from a sample of breath how much alcohol might be present in the blood using a conversion factor called the "partition ratio." California's breathalyzer machines assume that the amount of alcohol in 2100 milliliters of breath is equal to the amount of alcohol in 1 milliliter of blood.
"Simply put, the machines all automatically convert the amount of alcohol tested in the tiny amount of breath taken from the suspect," California DUI attorney Lawrence Taylor explained. "The internal computer multiplies the amount by 2100 -- using the average ratio of alcohol in blood to alcohol in breath -- to estimate the amount of alcohol in the suspect's blood. Problem: We are not all average. And ratios vary from 1300:1 to 3500:1...[Y]ou can use scientific facts that the BAC reading is faulty to defend yourself against the BAC-based presumption of being under the influence -- but not against the charge that your BAC was .08 percent or higher."
Would a little more math knowledge help these judges? Or are they stupid anyway?