Calif court: breath test accuracy can vary

SAN FRANCISCO (AP) - July 9, 2009 The unanimous high-court decision issued Thursday means suspected drunken drivers can attack the accuracy of roadside breath test results in some cases.

Studies have shown the breath-to-blood ratio varies widely among different people and even in the same person depending on such factors as health, menstrual cycle and even the weather.

The one-size-fits-all tests determine the amount of alcohol in the breath and then, using a scientific formula, converts that figure into an estimation of alcohol in the blood.

Lawyers say juries in several other states already are allowed to consider the test's variability.