Five Categories of Evidence Used in Massachusetts OUI Cases.

Evidence in a drunk driving case generally falls into five categories. The first of these consists of driving symptoms that lead to traffic stops. These include weaving in and out of lanes, braking repeatedly, lane straddling or erratic driving. According to the National Highway Traffic Safety Administration (NHTSA), there are as many as 20 different driving patterns recognized to be possible indicators of intoxication.  I scrutinize the basis the traffic stop and challenge them with a motion to suppress if the police did not have an adequate basis for the stop.

The second type of DUI evidence involves personal behavior and appearance, which the police officer notices when he or she approaches the vehicle. These can include an odor of alcohol on the breath, bloodshot eyes, slurred speech, unsteady walking and leaning on the car for support. Some of these are so common that officers include them in their arrest reports — even if the behavior was not actually present.  The testimony regarding behavior in a trial can often be challenged since the officer’s opinions are often subjective.

The third type of evidence consists of the results of field sobriety tests.  These may include walk and turn, touch the nose, one-leg stand and the horizontal gaze nystagmus test. This test involves following an object like a pen or finger from side to side with your eyes. Each test must be administered correctly, and the results are not always reliable.  The officer’s conclusions about the performance of field sobriety exercises can be challenged, since the opinion as to how someone performed is not scientific but subjective.

The fourth category of evidence consists of incriminating statements. These may be made during questioning or just spontaneously.

The final type of DUI evidence is the blood-alcohol test. These may be blood tests, breath tests or urine tests. Experienced DUI defense lawyers know that the computer in the breath-test machine (Breathalyzer) assumes the person is average when this is not always the case. Mistakes in test administration, food and some medications can all affect the accuracy of the Breathalyzer.  As of now, the breath test is considered unreliable by the courts in Massachusetts, and the results are not admissible.  Failre to take a breath test can still result in administrative penalties.