CR30-011. Definition of “Alcohol Concentration” (02/11/02). Under the statutory definition, the “alcohol concentration” may be stated as a number, without corresponding units. Thus the number 0.15 may refer to 0.15 grams of alcohol per 100 milliliters of blood, or it may refer to 0.15 grams of alcohol per 210 liters of breath. Although the “alcohol concentration” may roughly correspond to the percentage of alcohol in the blood by weight, it is potentially confusing, and incorrect under the statutory definition, to refer to the number as a percentage, such as 0.15 %.
CR30-031. Definition of “Under the Influence of Intoxicating Liquor” (05/08/03). The Supreme Court has repeatedly upheld an instruction that a driver was “under the influence” if he or she was affected “in the slightest degree” by intoxicating liquor. This so-called “Storrs instruction,” based on State v. Storrs, 105 Vt. 180, 185 (1933), is appropriate “in cases where testimony supports a claim of loss of control of physical and mental faculties, [but] not where the evidence deals solely with the chemical level of alcohol.” State v. Carmody, 140Vt. 631, 638 (1982).
A layperson may testify about his or her observations supporting a conclusion that the defendant was under the influence. State v. Baldwin, 140 Vt. 501, 515 (1981). “Recognition of the fact of intoxication requires no particular scientific knowledge or training.” State v. Coburn, 122Vt. 102, 107 (1960).