The Field Sobriety Tests
Standardized Field Sobriety Tests (SFST) are psychophysical tests. A test is an "objective" and "standardized" measure of a sample of behavior, focusing on three elements:
1) Objectivity: Aspects of a test are based on objective criteria, such as the scoring or the interpretation of the score, and not influenced by the subjective opinion of examiner.
2) Standardization: There is uniformity of procedure in the administration, scoring and interpretation of the test and results.
3) Behavior Sample: A representative sample of a person's behavior from which one can draw inferences and hypotheses.
A test is not a psychological X-ray, nor does it necessarily reveal hidden conflicts and forbidden wishes.
Psychological tests must meet three criteria: (1) Reliability, (2) Standardization, and (3) Validity. Tests are used by a variety of professionals, including psychologists, special-education teachers, guidance counselors, psychiatrists, speech therapists, nurses and engineers.
Psychophysical tests should require evaluation of the subject's appearance and condition, ability to follow instructions, as well as balance and coordination. These types of tests are called Divided Attention Tests, for they require the subject to concentrate on more than one thing at a time, dividing the subject's attention between mental and physical tasks. Studies have shown that a person who is under the influence of an alcoholic beverage may be able to perform one of these tasks but rarely both. If under the influence of an alcoholic beverage, people are likely to make certain predictable errors while attempting these tasks. Since the mid 1970's, the National Highway Traffic Safety Administration (NHTSA), with the cooperation and assistance of the law enforcement community, has conducted research that resulted in the development of a battery of three standardized field sobriety tests: Horizontal Gaze Nystagmus, Walk and Turn and the One Leg Stand to assist police officers in detecting impaired drivers.
The program, which was previously termed the Improved Sobriety Testing, was validated in laboratory and field studies conducted by the Southern California Research Institute. These tests were initially developed by the Los Angeles Police Department and the methodology of conducting these tests is included in the NHTSA course "DWI Detection and Standardized Field Sobriety Testing."
In 1986, the Advisory Committee on Highway Safety of the International Association of Chiefs of Police (IACP) passed a resolution which recommended that law enforcement agencies adopt and implement the field sobriety testing program developed by NHTSA. As the program grew, it became apparent that in order to insure continued success, nationally accepted standards should be established. Standardization that established criteria for the selection and training of SFST practitioners would help insure the continued high level of success of the SFST program. In 1992, the IACP Highway Safety Committee recommended the development of this system of nationally accepted standards.
In April of 1992, the IACP and NHTSA sponsored a meeting at the headquarters of IACP in Arlington, Virginia. Persons invited to this meeting included SFST instructors from several states, curriculum specialists and training administrators. The participants met in working groups to reach a consensus concerning the many issues relating to the SFST program and to develop recommended minimum standards to the IACP Advisory Committee on Highway Safety. The standards were drafted and presented to the committee for their review at the mid-year meeting in June 1992.
The Advisory Committee on Highway Safety by resolution adopted the National Standards for the SFST Program and voting membership of the IACP subsequently approved the Standards. In order to maintain the credibility and integrity of the program, agencies that use a training program other than that which is currently approved by the IACP must have the alternative curriculum approved by the IACP Advisory Committee on Highway Safety as meeting the required learning objectives. This is supported by the National Highway Traffic Safety Administration. Presently, SFST Training for Police officers (and the few DUI Defense Attorneys, including Attorney Ruane, who have been taught the regimen) must be 16 hours in length and include at least two controlled drinking sessions utilizing volunteer drinkers. This is in accordance with section 1.2 of the Standards for Training in Standardized Field Sobriety Testing. In section 1.4, in order to satisfactorily complete the classroom portion of the training, SFST candidates must complete the IACP-approved final examination with a score of not less than eighty percent. Candidates scoring less than 80% on the final may be re-tested one time under the supervision of a SFST instructor. The retest shall be completed not less than 15 days and not more than 30 days following the completion of the classroom training, and the examination used shall not have been administered to the candidate previously. If the candidate does not achieve a passing score on reexamination, the candidate must retake the classroom portion of the training and pass the final examination.
The U.S. DOT requires 35 practice tests within a six month period, but local and State Police have varying requirements based on their own department’s criteria. A refusal of a chemical test cannot be considered a practice test, as a blood alcohol reading must corroborate the evaluation of the suspect. The officer is trained to conduct the HGN test last during his practice test period and not to formulate an opinion based on the results or use it for probable cause to arrest. They are told not to document the test due to this.
At no time may a person that is tested be used more than once on a practice test. As a result of this it is necessary to review the documentation of the practice tests in order to determine if the practitioner was properly recommended for certification.
After probable cause is determined, an officer will most often attempt to recover more evidence that the driver is under the influence of drugs or alcohol and an officer may ask a person to perform Standardized Field Sobriety Tests. In every state you do not have to take field sobriety tests, but in each state the law is different regarding whether or not you have to consent to a blood breath or urine test. Standardized Field Sobriety Tests, usually conducted on the side of the road, do nothing to prove your sobriety, and oftentimes can hurt your defense. The officer cannot force you to do these tests, so politely decline. However, in Connecticut, while you do not have to take a blood, breath or urine test, a refusal will trigger a longer DMV administrative suspension. If an officer tells you he will let you go if you take them, you should still decline. They can only add to the probable cause for your arrest.
Generally there are three "tests" which are administered on scene. These tests are the Walk and Turn, the One Leg Stand, and the Horizontal Gaze Nystagmus. The three tests are most often used together and have shown 93% accuracy in Colorado in 1995, 95% accuracy in Florida in 1997 and 91% accuracy in San Diego in 1998, however, there are many scientists who refute the validity of these tests. The Horizontal Gaze Nystagmus is still the most accurate of the three and is said to “provide valid indications to support arrest decisions at 0.08 and strongly suggests that it can provide valid indication of 0.04 and above.” When the Horizontal Gaze is combined with the Walk and Turn it is said to have 80% accuracy, but it is obvious that when tested with all three there is a higher degree of accuracy. These three tests, however, have never been subject to peer review. (Peer review is the process in which scientists publish their methods and results to other persons in their field to allow for critical analysis of the data and results.)
Field Testing will most often occur on the side of the road after one has been suspected of being under the influence. The results of the test will help the officer to support evidence if they find you to be under the influence of drugs or alcohol.
You can simply tell the officer that you do not wish to take the tests. Remember to be polite with the officer because it can only help you later but refraining from field tests is your right. They are not required and in most cases will only hinder you when it comes time for court. Conditions for field-testing are often not ideal with uneven ground; poor lighting, weather and even improper attire and footwear could hinder accurate results.
Horizontal Gaze Nystagmus
The suspect must be instructed to look straight ahead, keeping the head still while following and focusing on the stimulus with the eyes until told to stop. The stimulus must be twelve to fifteen inches in front of the suspect's eyes for ease of focus. The officer is trained to receive an acknowledgement from the suspect that the stimulus is at a comfortable distance from the suspect's eyes and to document this confirmation. Even though this test is not a vision test, per se, eyeglasses are to be removed in order for the officer to make a more accurate determination of the final total points. If the suspect can not see the stimulus after removing the eyeglasses, they must be allowed to perform it with them on. According to the manual, hard contact lenses are to be removed so as to avoid dislodging when the eyes are out at maximum deviation or to prevent damage to the eyes.
A person with a glass eye or only vision in one eye can not be given this test for evaluation of just one eye and then a subsequent doubling of the score, assuming that the other eye will render the same results, is both erroneous and improper. If the suspect has what is known as the lazy eye condition, the officer is trained to test one eye while the other eye is covered by the suspects’ hand, then to switch same. A person who is color blind is not validated for this test as they will probably have a pathological Nystagmus which is normal and natural for that condition. This can be caused by some type of neurological disorder, brain damage, epilepsy or pathological disorder which the suspect is born with or of unknown etiology. A large disparity between the right and left eye can clue the officer into this problem. At an accident scene, if the suspect sustains a concussion, this may bring on a pathological Nystagmus thereby invalidating this test.
Although very few test conditions affect gaze Nystagmus, there are certain administrative procedures that must be followed. As previously mentioned, the stimulus must be placed twelve to fifteen inches in front of the suspect's eyes. The stimulus should be held above eye level, so that the eyes are wide open and looking directly at it. Due to narrowness of certain individuals’ eyes it becomes more difficult to make a fair evaluation of the Nystagmus unless the eyes are wide open.
If the officer believes that the Nystagmus might be there, it can not be scored, as the benefit of the doubt must be given to the person that is being tested. The officer is also trained to administer this test with the suspect looking into a quiet background, facing away from police cruisers and oncoming traffic. This is to avoid the probability of evaluating an induced condition known as optokinetic Nystagmus, which develops when a person focuses on several objects at one time or on objects that are moving away. This optokinetic Nystagmus is a defense mechanism of the body in order to keep the eyes from tiring. There are numerous visual or other distractions that may also impede this test. Certain environmental factors such as wind and dust may interfere with the performance of the Nystagmus test. When administered alone, Horizontal Gaze Nystagmus is considered to be 77% accurate by the law enforcement community.
First Clue: Lack of Smooth Pursuit
As explained earlier, Nystagmus is the involuntary jerking of the eyes. With alcohol intoxication, three clues will be sought after, the first of which is smooth pursuit. The officer is trained to look for the suspect's inability to pursue a stimulus smoothly moving horizontally while focusing on that. If the suspect moves his head to the side at any time, the score may be invalid regardless of which clue the officer is looking for. An example of smooth pursuit is a marble rolling across a smooth pane of glass: this would be a very smooth pursuit. If the suspect is under the influence, the eyes will bounce or jerk in similar fashion, as if that same marble was rolled across a piece of sandpaper. The officer is instructed to check the left eye first by moving the object to the officer's right. The object must be moved smoothly in order to comfortably bring the suspect's eye as far to the side as it can go. Any choppy or shaky hand movements or movement that is too fast by the officer may induce a Nystagmus in the suspect's eyes and invalidate the test. The officer is instructed to make two or more passes in front of the eye to be absolutely certain that there is a Nystagmus. If this clue is scored as Nystagmus the suspect is assessed one point. However, if the suspect has this clue emanating in one eye, it is not guaranteed that it will be exhibited in the other eye.
Second Clue: Distinct Jerkiness at Maximum Deviation
After the officer has checked the first eye for the smooth pursuit clue, the same eye must be checked for distinct jerkiness at maximum deviation. This is accomplished by simply moving the object to the side until the eye has gone as far to the side as possible. At maximum deviation, no sclera or “white” will be showing in the corner of the eyeball. The officer must hold the eyeball at that position for two or three seconds and attempt to discern distinct eyeball jerkiness. If the officer can not make this distinction from a slight Nystagmus, the benefit of the doubt must be given the suspect. The officer may make the mistake of not bringing the eyes out to side as far as they can go or too rapidly returning the stimulus and incorrectly score this part of the test. During the test, a certain degree of uncomfortableness is experienced, causing a slight twitching of the eyes at maximum deviation and if the officer returns the stimulus too quickly, the natural Nystagmus may be mistaken for that caused by intoxication.
Final Clue: Angle of Onset
Although the most difficult to evaluate, the angle of onset is perhaps the greatest indicator of the presence of the other clues. This correlation, however, does not work conversely. The presence of either of the first two clues does not guarantee that the third clue will be present.
The person is told to follow the stimulus until they are looking down a 45-degree diagonal. In order to estimate the 45-degree angle, the officer is told to place the stimulus halfway between the suspect's ear and nose on the side being tested or just outside the shoulder area. The estimation of this angle is critical, since studies have shown that as the alcohol increases, the angle will decrease. Although this may be the case, this angle should not be used to estimate a specific amount of alcohol in the bloodstream.
To score this part of the test, the officer must move the object to a 45-degree angle so the eye matches this angle, looking for jerkiness in the movement. If Nystagmus is observed, the stimulus is stopped and the officer must make note a continued jerkiness. If it does continue, the officer must observe whether there is still white showing in the corner of the eye and then the angle is noted as prior than 45-degrees. If there is no jerkiness, the stimulus must continue to be moved until the jerking occurs or the 45-degree angle is reached. If no white of the eye is showing, the eye has either been taken too far to the right, which would indicate maximum deviation, or the person has unusual eyes that will not deviate very far to the side. The criterion of onset before 45-degrees only can be used if some white can still be seen at the outside of the eye, however, too often the officer incorrectly estimates the angle or scores this with no white showing in the corner of the eye or both.
This test is deemed the most reliable test in determining probable cause to believe someone is under the influence of an alcoholic beverage; however this obviously depends on whether the officer adheres to the proper administration and proper scoring of the test.
This test should not be administered if the suspect is lying down but can be administered to them if they are sitting or standing.
Walk and Turn Field Test
Correct administration of this field test requires that it be performed on a hard, dry, level, non-slip surface with sufficient room for the suspect to complete nine heel-to-toe steps. This test does in fact lose some validity when conducted in certain wind or weather conditions that prevent the standards of administration from being met. The manual calls for a straight line, which must be clearly visible on the surface, however it is taught that the test can be performed parallel to the curb. Conditions must also be such that the suspect would be in no danger if he or she were to fall.
Some people should not be given this test because even the average sober person would have difficulty with it. People more than sixty five years of age or over fifty pounds overweight or with any physical impairment that would affect their ability to balance should not be given this test. The officer is trained to take this into account when developing their probable cause for arrest. Individuals wearing heels more than two inches high should be given the opportunity to remove their shoes, as this may affect the subject’s ability to balance and subsequently hinder the validity of the results. Individuals who can not see out of one eye may also have trouble with this test because of poor depth perception and should not be given this test as well.
The Walk and Turn test is an objective test based upon certain predictable errors that a person under the influence will display, as well as scoring factors that will give the officer a basis for passing and failing other than a subjective opinion. In order to properly administer this test, it is important to understand what type of test this is. It is commonly referred to as a Divided Attention Test because it divides the suspect's attention between mental and physical tasks. The physical tasks include balance and coordination while the mental tasks include comprehension of verbal instructions, the processing of information and the recall of memory. While a person may be able to perform one task, they may not be able to perform the other if under the influence of an alcoholic beverage.
While the suspect is performing this test, the officer must observe the suspect from three or four feet away and remain motionless. Being too close or creating a distraction with excessive motion may cause the suspect to make errors they may not have committed otherwise. This will cause some validity of the results to be lost as even a sober person may have difficulty under these particular conditions. The officer must give clear verbal instructions, only to supplement this with a demonstration of the test, and must receive affirmative confirmation of the suspect’s comprehension of the instructions.
This test is scored in relation to eight scoring factors that can be seen in two separate stages. When administered alone, the Walk-and-Turn test is considered to be 68% accurate, however, when combined with the Horizontal Gaze Nystagmus, the two are considered to be 80% accurate in detecting impaired drivers. The first stage of this test is called the Instruction Stage and will set the stage for the entire test. If the officer does not follow training and procedure perfectly during this stage, it may affect the validity of the entire test. The officer must verbally explain to the suspect the heel to toe stance and then demonstrate it. The suspect is told to place their left foot on the line and place their right foot on the line ahead of the left foot, with heel of right foot against toe of left foot. In the absence of a demonstration, instructions alone can discredit the validity of the test.
The officer is instructed by way of training to make sure the right foot is in front of the left foot to start in order to maintain uniformity. This also becomes important later in the test during the turning evaluation. If the suspect is instructed or demonstrated improperly, it may affect the suspect during this part of the test. After accomplishing the starting position, the officer must inform the suspect to remain in that position until they are told to start walking.
There are two ways that the officer can assess a point against the suspect's performance. If the suspect cannot keep balance while listening to the instructions, a point is scored. This item is only scored if the suspect does not maintain the heel to toe position throughout the instructions. The officer is trained to be conservative in their scoring and not to score a point if the
suspect sways or uses the arms to balance but maintains the starting position during this stage. A second scoring factor is known as starting too soon. This is given when the starts to walk before the officer instructs them to do so. This can only be scored if the officer specifically instructed the suspect not to start until told to begin and the suspect stated they understood this instruction.
The second stage of this test is known as the Walking Stage. The suspect is informed again, that when told to start, they must take nine heel to toe steps, turn around, and take nine heel to toe steps back. The officer must demonstrate two or three heel to toe steps for the suspect, as well as how to turn: the foot must be kept on the line and turn by taking a series of small steps. The officer then continues to instruct the suspect to keep their arms at their sides while walking, watch their feet at all times, to count their steps aloud and not to stop once they have begun. If the officer does not once again confirm the suspect’s understanding of the instructions, the test results may be invalid.
Scoring the Walk and Turn
There are six scoring factors that can be observed in this stage, the first of which is if the suspect stops to regain balance once the test has started. The officer can not score this item if the suspect is merely walking too slowly, but can only score this if the suspect pauses for at least several seconds after one step. Once this occurs, the officer is to have the suspect begin from the point of difficulty instead of starting over, as this test loses sensitivity if repeated several times. Another scoring factor is referred to as not touching heel to toe. If the suspect leaves a one half inch or more between the heel and toe or does not walk straight along the line they can only be assessed one point, no matter how many times this occurred.
During the instruction stage, if the suspect sways or uses their arms for balance a point can not be scored. A point can only be scored if during the walking stage, the suspect raises one or both arms more than six inches from the side in order to maintain balance. If this is noticed to be the normal position of the arms, as in some bodybuilders, the officer is trained to take that into account and be conservative in their scoring. The benefit of the doubt must be given to the suspect.
The next way a suspect can be given a point is if they lose balance while turning. This item can only be scored if the suspect removes both feet from the line while turning or does not take several small steps, and pivots in one movement, as in an about face movement. It is imperative that the officer has demonstrated and articulated this movement properly in order to be scored.
Finally, the last scoring factor is if the suspect takes the incorrect amount of steps. This item is scored only once, even if an incorrect amount of steps is taken in either direction. The suspect is also instructed to look down at their feet while performing this stage of the test and to count their steps out loud, however, if they don't adhere to these instructions, they can not be scored a point, as these are not one of the scoring factors.
There are two ways that the suspect can receive a maximum of eight points on this test. The first occurs if the suspect steps off of the line three or more times, and the second if the suspect can simply not do the test. If the suspect receives at least two total points on this test, the officer is trained to use this as probable cause to believe that the suspect is under the influence of an alcoholic and to make an arrest.
One Leg Stand Field Test
In order to accurately administer this test, the officer must move the suspect to a hard, dry, level, non-slippery surface. Conditions must be such that the suspect would be in no danger if he or she were to fall. Certain wind or weather conditions obviously may interfere with and affect the validity of this test. This test should not be given to persons who are more than sixty-five years of age, more than fifty pounds overweight, or with physical impairments that interfere with balance. Individuals wearing heels more than two inches high should be given the opportunity to remove their shoes as this may diminish the reliability of the results. The officer is trained not to give this test if there is not adequate lighting to perform it. In total darkness, even the average, sober person may have difficulty with this test as a result of a lack of visual frame of reference that would otherwise be provided with proper lighting.
As with the Walk and Turn Test, it is imperative that the officer observes the suspect from at least three feet away and remain as motionless as possible so that there are absolutely no distractions caused by the officer.
In the administration of this test, there are also two separate stages involved. The first stage is also called the "Instruction" Stage. The test is initiated by giving verbal instructions, followed by a demonstration. The officer is trained to advise the suspect to stand with their heels together and arms down at their sides and to not start the test until told to do so. As before, the officer must receive affirmative confirmation that the suspect understood the instructions and then document this acknowledgment. There are no scoring opportunities until the next stage of the test, the Balance and Counting Stage, unless the suspect can not even perform the test, which would of course be scored. This would give the suspect a maximum score of four points and would necessitate explanation on the part of the officer.
At the start of the "Balance and Counting" Stage, the officer is required to explain the test requirements further by instructing the suspect to stand on one leg (the suspect can choose which), holding the other foot in front about six inches from the ground. While standing, the suspect must keep their arms at their sides, look only at the extended foot, refrain from swaying or hopping, and count out loud for 30 seconds, counting each second as "one-one thousand.” The officer then demonstrates all of the above mentioned instructions including the counting and asks for acknowledgment of comprehension, at which point if received, the test begins.
Scoring the One Leg Stand:
A suspect may be scored a point for the following reasons:
1. Suspect sways while balancing. The officer is trained not to be too critical in this scoring as the suspect is human and some sway is a natural reaction. The swaying that can be scored is a marked sway, such as a back-and-forth motion while the suspect maintains the position.
2. The suspect uses the arms for balance, raising six or more inches from the side of the body. The officer must take into account the natural position of the arms, as in the case with body builders, for some the natural position of the arms may be farther than six inches. If the suspect puts their foot down, regardless of how many times, they can only be given one point. The suspect
should be allowed to continue from the point of difficulty as this test may lose sensitivity if repeated several times. The suspect has been instructed to keep watching their raised foot and to count out loud, but if they do not follow either of these instructions, they are not scored any points. If the suspect counts too slowly, it is imperative that the officer stop the test after thirty seconds have elapsed as this may affect the scoring and validity of the test. The officer is trained to time thirty seconds of total test time. If the suspect counts too fast the officer is instructed to slow them down.
3. The last scoring factor in this test is whether or not a suspect hops on one foot. This is scored only if they resort to hopping on the anchor foot in order to maintain balance. It should not be scored if the suspect is having difficulty by moving the anchor foot back and forth. The officer is supposed to be able to distinguish this as part of their training and to allow the suspect this benefit.
The suspect can receive a maximum score on this test in two ways, the first of which would happen if the suspect puts their foot down three or more times during the thirty second count. Secondly, if the suspect can not perform the test as a result of their intoxication level, they are then scored the maximum; however, the officer must be able to articulate why they felt the defendant was incapable. The degree of reliability of this test is 65% if instructed and scored properly.
For purposes of the arrest report and courtroom testimony, the officer is trained that it is not simply enough to report the suspect's "score" on the three tests. The numeric scores are only important to the police officer in the field to determine probable cause, however merely a score is insufficient to secure a conviction and must be accompanied by more descriptive evidence. The officer must be able to describe in detail how the suspect performed, and the manual provided to the officer has a standard note-taking guide which should be utilized to assist the officer and prove the case.
Sobriety Tests Not Yet Validated
Counting Backwards
This divided attention test requires a person to count out loud a set of numbers in reverse order. For example, the person is instructed to count starting with 56 and ending with 28. This divides the person's attention because they have to remember what number to start with, count backwards correctly, and remember what number to stop on. Anything other than 100% perfection will be viewed as a sign of intoxication.
Alphabet
This test requires a person to recite a portion of the alphabet. For example, the person is instructed to start with a specific letter, D, and stop at a specific letter, T. This divides the person's attention because they have to remember the specific letter to start with, say the letters in sequence, and remember the letter to stop with. Anything less than 100% perfection will be viewed as a sign of intoxication.
Finger Count
This test required a person to touch the tip of each finger in succession to the tip of their thumb, up and back, while counting 1, 2, 3, 4, .. 4, 3, 2, 1. They must touch fingertips while not counting out of order. Anything less then 100% perfection will be viewed as a sign of intoxication.
Stationary Balance (i.e. Rhomberg)
This test requires a person to stand with heels and toes touching, leaning their head back to look up at the sky or ceiling, holding their arms out to the side (like an airplane) and estimate 30 seconds. The officer is looking for any unnatural sway. I have had officers testify from a range of anything more than ½ inch to 1 inch from center is too much sway and must be caused by intoxication. Also, if your estimation is not close to 30 seconds, this will be viewed as a sign of intoxication.
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