Court Upholds Breath Test for Drunk Drivers : Laws: State justices reject challenges based on the argument that the exams don’t accurately reflect blood-alcohol level.

Ushering in the holidays with a warning to drunk drivers, the California Supreme Court ruled Wednesday that breath tests can be used to establish intoxication even though they may not reflect the amount of alcohol in the blood.

The court, in a 6-1 decision, held that a 1990 law passed by the Legislature makes it illegal to drive with a specified level of alcohol either in the blood or in the breath.

Before the law, prosecutors had to prove a blood-alcohol concentration of 0.08%. Suspects who took the breath test could challenge the state formula for converting breath measurements to blood levels. Now the conversion process will be irrelevant in such cases.

Justice Stanley Mosk, who wrote the majority decision, said the court’s interpretation of the law “promotes the state’s interest in reducing the danger to the public caused by those who drink and drive.”

“It will increase the likelihood of convicting such a driver,” Mosk wrote, “because the prosecution need not prove actual impairment.”

Drivers who are suspected of drunk driving are allowed to choose a urine, breath or blood test. But the formula used to convert urine and breath readings to blood measurements may not be accurate for all individuals. Body temperature, gender, medical conditions and other factors can influence the measurements.

Stephan Van Decker, an Imperial County deputy public defender who represented two Brawley motorists in the case before the court, said the blood test is the most accurate measure, followed by breath and urine measurements. Most suspects choose the breath test because it can be administered on the scene.

Justice Joyce Kennard, in a dissenting opinion, complained that the majority created a new crime of “driving with alcohol in the breath.”

The defendants, Donald E. Bransford and Ralph Maldonado, were arrested in separate incidents in 1991 after breath tests detected excessive amounts of alcohol in their systems.

They were not allowed to challenge the reliability of the conversion formula in court because judges interpreted the new state law as requiring only evidence of alcohol in the breath, not the blood, for conviction. A Court of Appeal upheld their convictions.

Van Decker, who defended them, said defendants will still be able to challenge urine test results.

“This means people are being treated differently depending on which test they take,” Van Decker said.

But Deputy Atty. Gen. Patti W. Ranger said the breath test works to the suspect’s detriment in only 2% of the cases. Most of the time, she said, it underestimates the level of alcohol in the blood.

“Especially for the holiday season,” she said, “I think this decision will greatly help our fight against the intoxicated driver.”