Driving Under the Influence (DUI)
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Introduction: What is Driving Under the Influence?
All 50 states and the District of Columbia define it as a crime to drive with blood alcohol concentration (BAC) at or above .08 percent. License suspension or revocation traditionally follows a conviction for alcohol-related driving. Your driver’s license can be taken before conviction when a driver fails or refuses to take a chemical test.
More than 17, 000 people are the victims of drunk driving accidents every year. Approximately 40% of all motor-vehicle fatalities are alcohol-related. In the United States, drunk driving is the leading criminal cause of death.
Drunk driving is considered a serious case in regards to driving violations. It may be referred to as Driving Under the Influence (DUI), or Driving While Intoxicated (DWI) or Operating While Intoxicated (OWI) in certain states. It is defined as the individual operating the motor vehicle has consumed enough alcohol to impair their driving ability. This is determined either by a blood-alcohol test (BAC) or by some other sobriety test conducted by the officer.
Field sobriety tests and chemical tests.
Field Sobriety Testing
During a DUI stop, an officer may ask a driver to submit to field sobriety testing. This can include performing any number of tasks to assess impairment of a person’s physical ability. Most people don’t realize that these tests are optional. You are well within your legal right to politely refuse to take the Field Sobriety Tests in their entirety. These non-chemical tests are subjective and designed to provide probable cause for the officer to arrest you. Individuals that are perfectly sober could fail these tests due to a disability, illness, poor coordination, tiredness or poor testing conditions, such as bad weather.
One of the most dangerous Field Sobriety Tests is the Preliminary Alcohol Screening test, also called the PAS test. This is a portable breath test to determine the presence of alcohol. The officer is supposed to advise the suspect that the test is voluntary, but often, they do not.
The National Highway Transportation Safety Administration (NHTSA) created a standardized model for field sobriety testing in 1981. The Standardized Field Sobriety Test (SFST) uses three tests in combination to obtain valid indicators of impairment and establish probably cause for arrest.
HGN Testing
Horizontal Gaze Nystagmus is an involuntary jerking of the eye that occurs naturally as the eyes gaze to the side. Under normal circumstances, this occurs when the eyes are rotated at high peripheral angles. When an individual is under the influence, Nystagmus is exaggerated and may occur at lesser angles. The officer may use a small penlight or flashlight to observe the suspects eyes as it follows a slowly moving object. The examiner looks for three indicators of impairment in each eye. If the eye cannot follow a moving object smoothly, this may indicate impairment. However, this test alone is not enough to secure an arrest.
Walking and Turning
These tests typically consist of walking a straight line and turning around and repeating the procedure. They require the suspect to following instructions while performing simple physical movements. An impaired person may have difficulty with tasks requiring their full attention.
One Leg Stand
Sometimes, the officer will request the suspect to stand on one leg with one foot approximately six inches off the ground and count aloud by thousands until they are instructed to put their foot down. The officer usually times the suspect for 30 seconds.
When all of the field sobriety tests are completed, officers are accurate in only 91% of their overall cases.