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Driving With 0.10% Blood Alcohol - Can the State Prove It?

NCJ Number
University of San Francisco Law Review Volume: 16 Issue: 4 Dated: (Summer 1982) Pages: 817-839
G J Donnellan
Date Published
19 pages
This analysis of California's 1981 law creating the new crime of driving with a .10-percent blood alcohol content (BAC) proposes amending the Vehicle Code to penalize driving after consuming enough alcohol to have a .10 percent or more BAC at the time of a test because proof of the BAC while driving is not feasible.
The legislature passed Assembly Bill 7, which does not require the State to show a relation between BAC and impaired driving, to streamline the adjudication of drunk driving cases. Recent studies, however, have seriously questioned the accuracy of the current scientific method used to extrapolate the BAC at the time of driving from the BAC at the time of a blood alcohol test. Research shows that the BAC at the time of a test may be significantly higher than the BAC when a defendant was driving. The method currently used to estimate BAC has presumed a defined absorption rate, a consistent time for a peak BAC, and a defined alcohol elimination rate. This ignores the fact that an individual BAC does not follow uniform patterns, but both alcohol absorption and elimination rates vary from hour to hour and from driver to driver. Thus, prosecutors will not be able to meet the burden of proof beyond a reasonable doubt that a defendant had a BAC of .10 percent or more while driving simply by showing the results of a BAC test administered some time later. The legislature already has recognized problems in the new law and reenacted the legal presumption for driving under the influence of alcohol. In addition to amending the code to penalize a BAC of .10 percent at the time of the test, the legislature should separate criminal punishment of drunk driving from the administrative suspension of the driver's license to increase the expectation of prompt punishment for drunk driving. Tables and 68 footnotes are provided.