In California, lawmakers have enacted two distinct crimes relating to DUI. One, VC 23152(a) requires proof of actual impairment. Section 23152(b), added in 1981, made it unlawful for a person to drive with a blood-alcohol level of 0.10 percent or more, by weight, and specified that, “percent, by weight, of alcohol shall be based upon grams of alcohol per 100 milliliters of blood.” To secure a conviction for this new “per se DUI” offense, the prosecution no longer had to prove the accused driver was actually impaired at the time of the offense, but only that heor she drove with a blood-alcohol level at or exceeding 0.10 percent. In 1989, the California Legislature further strengthened our state‟s DUI laws by lowering the punishable blood-alcohol threshold from 0.10 percent to 0.08 percent. This is the proscribed level today
Therefore, after 1981 there were two parallel statutes making it a crime to drive while intoxicated. The generic DUI provision (§ 23152(a)) retained the historical approach, requiring proof that the defendant was actually impaired by his drinking. The per se DUI statute (Vehicle Code 23152(b)) simply required proof that the defendant had been driving with a blood-alcohol level over the legal limit. If the limit was exceeded, the statute was violated, and no additional proof of the defendant‟s impairment was required. The interplay between the two statutes can often be confusing for laymen, an attorney should be consulted to explain the interaction of the two offenses in your case.