Standardized Field Sobriety Testing
Many New Jersey Police Officers are trained and certified in the administration of what is known as Standardized Field Sobriety Testing (SFST). Standardized Field Sobriety Testing is a battery of three tests administered and evaluated in a standardized and objective manner to obtain validated indicators (called “cues”) of impairment and to establish probable cause to arrest a DWI suspect. These tests were developed as a result of research sponsored by the National Highway Traffic Safety Administration (NHTSA). Formal training (and certification) in the administration of Standardized Field Sobriety Testing consists of intensive class room study, at least two controlled drinking sessions testing subjects, and a final written examination.
The three Standardized Field Sobriety tests are: (1) the horizontal gaze nystagmus (HGN), (2) the walk-and-turn, and (3) the one-leg-stand. NHTSA training suggests that SFST is reliable in identifying subjects whose B.A.C.s are .10% or more. The reliability of SFST is, however, completely contingent upon the tests being administered in a prescribed, standardized manner, standardized indicators (“cues”) being used to assess the suspect’s performance, and standardized criteria being employed to interpret the performance.
HORIZONTAL GAZE NYSTAGMUS (HGN)
Horizontal gaze nystagmus is a naturally occurring involuntary jerking of the eyeballs as they gaze side to side. It is theorized that when a person is impaired by alcohol, the nystagmus (the jerking of the eyeballs) is magnified or pronounced.
In the HGN test, the officer is trained to observe the eyes of a suspect as he follows a slowly moving object such as a pen or small flashlight (referred to as a “stimulus”) back and forth (horizontally). The stimulus is held 12-15 inches in front of the subject’s nose, with the tip slightly above the eyes. As the suspect tracks the stimulus (with his head remaining still), the officer is trained to look for three indicators (or cues) of impairment in each eye:
(1) the eye cannot follow the stimulus smoothly (like marble being rolled across a piece of sandpaper as opposed to a marble being rolled across a glass table), (2) distinct nystagmus when the eye is at maximum deviation (maximum deviation meaning the eyeball moved horizontally as far as it can go), and (3) the angle of onset of nystagmus is prior to 45 degrees from center (45 degrees being approximately when the eye is near the subject’s shoulder blade).
Officers are trained that if a suspect exhibits four or more cues, there is a 77% probability that he has a B.A.C. of .10 or more.
WALK AND TURN
There are two stages in the walk-and-turn test: (1) the instruction stage, and (2) the walking stage. In the instruction stage, the subject is directed to stand on a line with his feet in the heel-to-toe position (left foot in front of right), keep his arms at his sides, and listen to instructions and not begin until being told to do so. The subject is instructed to take nine steps, heel-to-toe, along a straight designated line while counting the steps out loud and watching his feet, and then turn and return in the same manner.
The officer is trained to look for four eight cues of impairment:
During the Instruction Stage:
1. loses balance during the instructions (by breaking away from the heel-to-toe stance),
2. starts walking before the instructions are finished,
During the Walking Stage:
3. stops while walking to steady self,
4. does not touch heel-to-toe (by missing by at least one-half inch),
5. steps off the line,
6. uses arms for balance (by six inches or more),
7. loses balance or turns improperly, and
8. takes the wrong number of steps.
Officers are trained to administer the walk-and-turn test on a hard, dry, and non-slippery surface, and in a well illuminated area. Officers are also instructed that people more than 60 years old, over 50 pounds overweight, or with physical impairments that affect their balance should not be given the test. Officers are taught that a straight line that the suspect can see must be used, and to remain motionless and stand three to four feet away from the suspect during the test. Last, officers are trained that individuals wearing heels more than two inches high should be given an opportunity to remove their shoes. Officers are trained that if a suspect exhibits two or more cues, there is a 68% probability that he has a B.A.C. of .10 or more.
ONE LEG STAND
There are two stages to the one-leg-stand test: (1) the instruction stage, and (2) the balancing and counting stage.
In the instruction stage, the suspect must stand with his feet together with his arms at their sides. The subject is instructed to stand with one foot of his choice approximately six inches off the ground, toes pointed out, and count aloud by thousands (One thousand-one, one thousand-two, etc.) while looking at the elevated foot until told to put the foot down. The suspect must be told not to hop or sway and not to use his arms for balance.
The officer is trained to look for four cues of impairment:
(1) swaying while balancing (a noticeable sway in a side to side or back and forth motion)
(2) using arms to balance (arms must raise from sides more than six inches),
(3) hopping to maintain balance, and
(4) putting the foot down.
Like the walk-and-turn test, officers are trained to administer the one-leg-stand test on a hard, dry, and non-slippery surface, and in a well illuminated area. Officers are also instructed that people more than 60 years old, over 50 pounds overweight, or with physical impairments that affect their balance should not be given the test. Officers are also instructed to remain motionless during the test and stand three away from the suspect. Last, officers are trained that individuals wearing heels more than two inches high should be given an opportunity to remove their shoes.
Officers are trained that if a suspect exhibits two or more cues, there is a 65% probability that he has a B.A.C. of .10 or more.
Officers are trained that the three Standardized Field Sobriety Tests (HGN, one-leg-stand, and walk-and-turn) are the only field sobriety tests which are scientifically validated in assessing intoxication (at or above .10 B.A.C.) Officers are trained that other sobriety tests (e.g., picking up coins, sway test, counting backwards) have no scientific validity and have a 50% chance of being able to accurately detect intoxication. Officers are, however, instructed (and it is very much emphasized) that the SFSTs are validated only when the tests are administered in the prescribed, standardized manner, and only when the standardized cues are used to assess the suspect’s performance, and only when the standardized criteria are employed to interpret that performance. If any of one of the standardized field sobriety test elements is changed, the validity is compromised.
This article does not intend to encompass all of the very specific and rigorous SFST Training, but rather, is merely an overview of the basic tenets of SFST. Any questions regarding the proper administration or scoring of SFSTs can be properly answered only after a careful and thorough review of all of the relevant facts and circumstances. The foregoing is provided for informational purposes only and not legal advice. Any questions regarding the law or the rights of any defendant should be reviewed by counsel engaged and provided with the defendant’s specific fact situation.