Basic Evidence

Evidence in a drunk driving case generally falls into several categories.

Driving.

This is usually what the police see first. It may involve weaving, lane straddling or erratic driving. Where you aware that there are 20 different driving patterns recognized by the National Highway Traffic Safety Administration which could be possible indicators of intoxication? Speeding is not one of these.

Appearance / Behavior.

These may include an odor of alcohol on the breath, bloodshot eyes, thick and/or slurred speech, flushed face, fumbling with a wallet to get the driver's license, unsteady gait, leaning on the car for support, difficulty following directions, etc. Some of these are odor of alcohol, bloodshot eyes and slurred speech which are encountered so often that some officers, trained to expect them, will include them in their arrest reports even if they are not actually present.

Field Sobriety Tests.

These may include walk-and-turn, one-leg-stand, modified position of attention (Rhomberg), alphabet, horizontal gaze nystagmus (HGN) (following the pen), fingers-to-thumb, hand pat, roadside breath test.

Statements You Make.

Chemical test.

Some of the evidence to establish the above can even be Circumstantial Evidence. For example, regarding proof that you were Under the Influence may be established by circumstantial evidence other than the results of a breath, blood, or urine test, e.g., slurred speech, unsteady gait according to Burg v Municipal Court (1983) 35 C3d 257, 266 n10, 198 CR 145. But proof that a defendant charged with a "per se" DUI violation had an 0.08 percent blood-alcohol level cannot be established by circumstantial evidence apart from a valid chemical test according to Baker v Gourley (2002) 98 CA4th 1263, 1273, 120 CR2d 348 (usual symptoms of intoxication can manifest themselves at a blood alcohol level below 0.08 percent).

Regarding your blood alcohol concentration you may have noticed that some websites use B rAC while other use BAC and they use inter change them with no regard for accuracy. B rAC means Breath Alcohol Concentration while BAC means Blood Alcohol Concentration and there is a big difference obviously since one measures your blood directly and the other measures your breath which is an indirect measurement of impairment. These two terms are connected however through what is called partition ration. This is something that your DUI lawyer should be aware of.

Regarding a defendant's refusal to take a required chemical test it (the refusal) is admissible to prove the defendant's consciousness of guilt, and the jury may be so instructed. Regarding the "driving" all that is required is "slight movement" of the vehicle in the arresting officer's presence constitutes direct evidence that the vehicle was being driven according to People v Wilson (1985) 176 CA3d Supp 1, 8, 222 CR 540. Additionally, moving the vehicle even a few inches constitutes driving pursuant to Music v Department of Motor Vehicles (1990) 221 CA3d 841, 850, 270 CR 692. Finally, if the arresting officer does not you driving the vehicle, proof that you were driving may be established by circumstantial according to Mercer v Department of Motor Vehicles (1991) 53 C3d 753, 762, 280 CR 745).