State DUI techniques and potential flaws:
There are many reasons for such driving mistakes other than DUI and Attorney Alexander
Illinois State and local police officers may use the Standardized Field Sobriety Test (SFST) consisting of three sections that have to be taken under a standard to note impairment sings which gives a probable cause for arrest. The three sections of the SFST called the horizontal gaze nystagmus (HGN), the walk-and-turn, the one-leg stand:
- Horizontal gaze nystagmus is an involuntary naturally occurring eyeball movement as the person looks to either side. Under normal circumstances, nystagmus occurs when the eyes are rotated at high peripheral angles. However, the SFST holds that when a person is impaired by some substance, nystagmus sings become more pronounced and is exaggerated and may occur at lesser angles. An alcohol-impaired suspect may struggle to track a moving object with her eyes as the officer observes the eyes slowly moving a pen or small flashlight, horizontally with her eyes. The officer must evaluate three possible impairment factors in each eye:
a. If the suspect’s eye fails to follow a moving object smoothly or visibly jerks at the eye maximum deviation or if the jerking occurs within 45 degrees of visual center.
b. If the officer determines that four or more clues present in both eyes, the suspect likely may have a BAC of 0.10 or greater in her blood. The scientific research indicates that this test achieves accurate evaluation of about 77% of suspects.
However, the test may produce a positive reaction if a person takes prescribed seizure medications like phencyclidine or certain inhalants, barbiturates, and other antidepressants. Again, the test may be scientifically justified yet, may be unreliable due to flawed expertise of the officer, improper test administering or erroneous clues interpreting at the scene.
2. Divided Attention Test: The field officers may subject a DUI suspect to the walk-and-turn test and one-leg stand. Both tests use a “divided attention” premise that most sober motorists are able to perform both tests well. However, the above tests require a suspected motorist to listen to and follow instructions while performing simple physical movements. Impaired suspects usually may struggle with tasks requiring divided special attention between mental and physical exercises. In the walk-and-turn test, an officer may request a suspect to take nine steps, heel-to-toe, along a straight line. After taking the steps, the officer must direct the suspect to turn on one foot and return same fashion to the starting test point. The officer in the field must consider seven impairment clues such as failure to keep one’s balance while being instructed, performs before the instructions completion, stops to regain the balance, fails to walk heel-to-toe, balances with arms, loses balance at turns or takes wrong number of steps. The research states that 68 % of tested suspects with two or more performance clues will have a BAC of 0.10 or greater. In the one-leg stand test, the field officer instructs to stand with one foot approximately six inches off the ground and count aloud by thousands such as one thousand-one, one thousand-two and so forth until the officer directs to place the foot down. The officer has to time the subject for 30 seconds and monitor for four of impairment clues: swaying while balancing, using arms to balance, hopping to maintain balance, and placing the foot down. The research indicates that 65 % of tested suspects with two or more noted clues during the test will have a BAC of 0.10 of greater. The test validity examined during a court hearing on the evidence gained on cumulative total impairment clues noted during the three part filled sobriety test battery.