10.56.050 Intoxication criteria.
Upon the trial of any civil or criminal action or proceeding arising out of acts alleged to have been committed by any person while driving or in actual physical control of a vehicle while under the influence of intoxicating liquor, the amount of alcohol in the person’s blood at the time alleged as shown by chemical analysis of his blood, breath or other bodily substance shall give rise to the following presumptions:
(1) If there was at that time 0.05 percent or less by weight of alcohol in the person’s blood, it shall be presumed that he was not under the influence of intoxicating liquor;
(2) If there was at that time in excess of 0.05 percent but less than 0.10 percent by weight of alcohol in the person’s blood, such fact shall not give rise to any presumption that the person was or was not under the influence of intoxicating liquor, but such fact may be considered with other competent evidence in determining whether the person was under the influence of intoxicating liquor;
(3) If there was at that time 0.10 percent or more by weight of alcohol in the person’s blood, it shall be presumed that he was under the influence of intoxicating liquor;
(4) Percent by weight of alcohol in the blood shall be based upon milligrams of alcohol per 100 cubic centimeters of blood;
(5) The foregoing provisions of this section shall not be construed as limiting the introduction of any other competent evidence bearing upon the question whether the person was under the influence of intoxicating liquor. (Ord. 299 § 2(b), 1969).