Circumstantial Evidence May Be Used to Bolster Blood Alcohol Test Results

Aug 30, 2013

The California Court of Appeals recently decided Coffey v. Shimoto, a case regarding rising blood alcohol after an arrest for DUI and the admissible evidence at a DMV administrative hearing regarding a license suspension.

In the case, Ms. Coffey was arrested for DUI. An hour later, she took a breathalizer test with a test result of .08 percent BAC. A few minutes later, her BAC test result was .09 %. Twenty-five minutes later, she took a blood test, which resulted in a BAC of .095 percent.

DMV suspended her license after a hearing at which the arresting officer testified that Ms. Coffey had driven “erratically,” appeared intoxicated, and had the usual script of bloodshot watery eyes, strong odor of alcohol, and poor performance on Field Sobriety Tests (FSTs).

She challenged DMV’s decision with a writ of mandate and argued that uncontroverted expert testimony showed that her BAC had been rising (as evidenced by the three test results). While the Court agreed with Coffey that the uncontradicted evidence of her rising BAC rebutted the presumption set forth in Veh. Code §23152(b) that a person had a BAC of 0.08 percent or more at the time of driving if a BAC test performed within three hours of driving reveals a level of 0.08 percent or more, the court concluded that DMV had produced sufficient additional evidence to prove that Coffey’s BAC was at least 0.08 percent at the time of driving. The Court pointed to circumstantial evidence: Coffey’s erratic driving, failed field-sobriety tests, and objective indications of intoxication were substantial evidence that Coffey had a BAC equal to or greater than 0.08 percent at the time of driving. Accordingly, the Court of Appeal concluded that the trial court had properly relied on this non-chemical test circumstantial evidence in concluding that Coffey’s BAC at the time of driving was consistent with her BAC at the time of her chemical tests.

Coffey v. Shiomoto, Cal.App.4th; August 15, 2013; G047562.