Field sobriety tests[edit]
Police administer a one-leg-stand test after a crash.
One of the most controversial aspects of a DUI stop is the field sobriety test (FSTs). The National Highway Traffic Safety Administration (NHTSA) has developed a model system for managing Standardized Field Sobriety Test (SFST) training. They have published numerous training manuals associated with FSTs. As a result of the NHTSA studies, the walk-and-turn test was determined to be 68% accurate, and the one-leg stand test is only 65% accurate when administered to people within the study parameters. The tests were not validated for people with medical conditions, injuries, 65 years or older, and 50 pounds or greater overweight. The officer will administer one or more field sobriety tests. FSTs are "divided attention tests" that test the suspect's ability to perform the type of mental and physical multitasking that is required to operate an automobile. However, these tests can be problematic for people with nonobvious disabilities affecting proprioception, such as Ehlers-Danlos syndrome. The three validated tests by NHTSA are:
horizontal gaze nystagmus test, which involves following an object with the eyes (such as a pen) to determine characteristic eye movement reaction.[30] walk-and-turn (heel-to-toe in a straight line). This test is designed to measure a person's ability to follow directions and remember a series of steps while dividing attention between physical and mental tasks. one-leg-stand. Alternative tests, which have not been scientifically validated, include:
modified-position-of-attention (feet together, head back, eyes closed for thirty seconds; also known as the Romberg test). finger-to-nose (tip head back, eyes closed, touch the tip of nose with tip of index finger). recite part of the alphabet (finger count) touch each finger of hand to thumb counting with each touch (1, 2, 3, 4, 4, 3, 2, 1). count backwards from a number ending in a number other than 5 or 0 and stopping at a number ending other than 5 or 0. The series of numbers should be more than 15. breathe into a "portable or preliminary breath tester" or PBT. Although most law enforcement agencies continue to use a variety of these FSTs, increasingly a 3-test battery of standardized field sobriety tests (SFSTs) is being adopted. The NHTSA-approved battery of tests consists of the horizontal gaze nystagmus test, the walk-and-turn test, and the one-leg-stand. In some states, such as Ohio, only the standardized tests will be admitted into evidence, provided they were administered and objectively scored "in substantial compliance" with NHTSA standards (ORC 4511.19(D)(4)(b)).[citation needed]
According to original studies conducted by NHTSA, these tests are not designed to detect impairment, but rather give a probability that a driver is at or above a 0.08% BAC. However, studies throw doubt on the tests' usefulness in helping an officer to judge either. In 1991, Dr. Spurgeon Cole of Clemson University conducted a study of the accuracy of FSTs. His staff videotaped people performing six common field sobriety tests, then showed the tapes to 14 police officers and asked them to decide whether the suspects had "had too much to drink and drive" (sic). The blood-alcohol concentration of each of the 21 DUI subjects was 0.00, unknown to the officers. The result: the officers gave their opinion that 46% of these innocent people were too drunk to be able to drive. This study showed the possible inaccuracy of FSTs.[31]
An increasingly used field sobriety test involves having the suspect breathe into a small, handheld breath testing device. Called variously a PAS ("preliminary alcohol screening") or PBT ("preliminary breath test"), the units are small, inexpensive versions of the larger, more sophisticated instruments at the police stations, the EBTs ("evidentiary breath test"). Whereas the EBTs usually employ infrared spectroscopy, the PAS units use a relatively simple electrochemical (fuel cell) technology. Their purpose, along with other FSTs, is to assist the officer in determining probable cause for arrest. Although, because of their relative inaccuracy, they were never intended to be used in court for proving actual blood-alcohol concentration, some courts have begun to admit them as evidence of BAC.
Critics of standardized field sobriety tests often question the statistical evidence behind them, and the ability of the officers to administer the tests and actually judge for impairments related to alcohol. According to Barone, one study involved completely sober individuals who were asked to perform the standardized field sobriety tests, and their performances were videotaped. “After viewing the 21 videos of sober individuals taking the standardized field tests, the police officers’ believed that forty-six person of the individuals had ‘too much to drink’” (Barone n.d.: 11). It should not be out of the question for the standardized field sobriety tests to be re-examined for reliability and validity. A standardized test that claims to have scientific support should be able to be repeated. Along with that, the standardized field sobriety tests do not have a specific standard for grading, and it is left up to the discretion of the officer. Humans make mistakes. The NHTSA’s 1977 study had an error rate of 47 percent, and the 1981 study had an error rate of 32 percent, which are unusually high for a scientific study (Barone & Crampton 2005).
One of the main ethical concerns of field sobriety tests is that judgment is left up to the discretion of the police officer. An officer may have some bias towards a suspect, and judge their test more critically than necessary. Along with that, it is almost impossible to tell whether or not a police officer has used proper procedures for administering the field sobriety test when a case is brought to court. The original research conducted by the NHTSA, along with following research of field sobriety tests is often disputed because of the manner in which they were conducted and the conclusions that were supposedly reached. “The reports for all three studies issued by NHTSA are lacking much of the material and analysis expected in a scientific paper, and none have been published in peer-reviewed journals” (Rubenzer 2011). Furthermore, a specific scale for signs of impairment due to alcohol has never been reached. This raises another problem, which is the fact that alcoholics have a much higher tolerance than the normal alcohol user. When being tested, they may be able to pass because they do not have the normal signs of alcohol impairment.
Walk-and-Turn Test
editSpecifically, the walk and turn test is composed of two phases, including the instruction phase and walking phase. During the test, the individual is directed to take nine steps along a straight line. The individual is supposed to walk heel to toe, and while looking down at a real or imaginary line, count the steps out loud. Making the test even more awkward, the arms must remain at their side. Reaching the ending point, the individual must turn around on one foot and return to the starting point. There are seven indicators of impairment that the police officer looks for: (1)Whether you are unable to maintain your balance while listening to the officer’s instructions; (2) whether you begin walking before the officer has completed the instructions; (3) whether you stop while walking in order to regain your balance; (4) whether you actually touch your feet heel-to-tow; (5) whether you use your arms to maintain your balance; (6) whether you lose your balance while turning; (7) whether you take an incorrect number of steps.[1]
One of the main problems with the walk and turn test is that some of the signs of alcohol impairment may stem from other physical problems. Along with that, there are other signs of physical impairment that can stem from various causes, including fatigue, an injury or illness, and nervousness. Those who are physically inactive, elderly, or obese may have trouble completing the walk and turn test without flaw. The NTSA used to say that those who are 50 pounds or more overweight may have difficulty performing the test, and that the suspect must walk along a real line. “Later NHTSA manuals removed the weight comment, and also inserted the phrase ‘imaginary line’ at the instruction phase, even though original research always used a visible line” (Barone n.d.: 8). The fact that officers are no longer required to provide a line for the suspect to walk along may affect the outcome of the test, and often adds to the scrutiny received from critics.