Field Sobriety Tests Massachusetts

If you have been arrested for OUI in Massachusetts, the officer probably had you do some field sobriety tests. (Hopefully, you refused to do the tests as they are voluntary and set-up for you to fail). If the officer had you do tests, he should have administered them and graded them a certain way. The officer will use his training based upon NHTSA guidelines. Attorney Hynes is certified not only to administer these tests, but to train officers.

There are three standardized field sobriety tests that are usually given. An eye test, a walking test, and a test to stand on one leg. These tests have many limitations. People often have difficulty doing the tests even if they are not impaired. Additionally, many officers do not administer the tests perfectly. In Massachusetts, the HGN test (eye-test) will often be inadmissible in the criminal case.

These tests can be difficult to administer and interpret. Good DUI defense means knowing everything about these tests. Attorney Hynes has an entire chapter of his book for other lawyers devoted to these tests. Here is some specifics regarding those tests:

Standardized Field Sobriety Tests

9. 5. 2 Horizontal Gaze Nystagmus (HGN)


The first test is the horizontal gaze nystagmus test (Pen/ Eye test). A nystagmus is an involuntary jerking of the eye. The officer, when moving a stimulus (pen, finger) across the person's face, is looking to see if the eye "jerks" instead of moving smoothly.

Based upon some research, by NHTSA, if someone has a nystagmus, there is a high probability that the person has a BAC of 0.10.(The 2006 student manual does not include the HGN Robustness study as it concluded was after the manual was released. This study shows just how much of a junk science HGN is, with incredibly high false positives).

There are a few different types of Nystagmus. The officer is looking for Gaze Nystagmus[1] Other types that may be relevant to a DWI defense include:

Post-rotational[2] (Nystagmus which is caused after a person stops spinning. Although, this usually only lasts a few seconds),

Caloric Nystagmus[3] - Caused when fluid in one ear is different in temperature than the other ear.(Which could possibly occur while a window is down, and cold rain entering one ear while the warm car heater is aimed at the other ear).

Optokinetic[4] Nystagmus - Occurs when eyes fixate on an object that suddenly moves out of sight, or when the eyes watch sharply contrasting moving images (Possibly if client is facing the officer's flashing blue lights/takedown lights.)

Resting Nystagmus[5] - Occurs when the eyes are facing straight ahead.

NaturalNystagmus - Some people have a natural nystagmus. Some officers will ask the person if they have it. I am not sure why the person would ever know if they had it.


However, one of the main problems with this test is THINGS OTHER THAN ALCOHOL CAUSE A NYSTAGMUS. For example: “It is undisputed that there are many factors that can cause nystagmus: problems in an individual's inner ear labyrinth; physiological problems such as influenza, streptococcus infection, vertigo, epilepsy, or measles; conditions such as eye muscle fatigue, sunstroke, or glaucoma; changes in atmospheric pressure; and consumption of substances such as caffeine, nicotine, or aspirin. See 1 R. Erwin, Defense of Drunk Driving Cases § 10.09[5], at 10-43 (3d ed. 1999) (Defense of Drunk Driving); M. Rouleau, Unreliability of the Horizontal Gaze Nystagmus Test, 4 Am.Jur.Proof of Facts 3d 439 § 9, at 455 (1989) (4 Am.Jur. POF 3d); National Highway Traffic Safety Administration (NHTSA), United States Department of Transportation (DOT), No. DOT HS-0806512, Improved Sobriety Testing (1984) (1984 NHTSA Instruction Manual), reprinted in 1 Defense of Drunk Driving § 10.99[2], app. at 10-93.[6]

One Court has specifically listed 38 different possible causes of nystagmus other than alcohol:

“(1) problems with the inner ear labyrinth; (2) irrigating the ears with warm or cold water under peculiar weather conditions; (3) influenza; (4) streptococcus infection; (5) vertigo; (6) measles; (7) syphilis; (8) arteriosclerosis; (9) muscular dystrophy; (10) multiple sclerosis; (11) Korchaff's syndrome; (12) brain hemorrhage; (13) epilepsy; (14) hypertension; (15) motion sickness; (16) sunstroke; (17) eye strain; (18) eye muscle fatigue; (19) glaucoma; (20) changes in atmospheric pressure; (21) consumption of excessive amounts of caffeine; (22) excessive exposure to nicotine; (23) aspirin; (24) circadian rhythms; (25) acute trauma to the head; (26) chronic trauma to the head; (27) some prescription drugs, tranquilizers, pain medications, anticonvulsants; (28) barbiturates; (29) disorders of the vestibular apparatus and brain stem; (30) cerebellum dysfunction; (31) heredity; (32) diet; (33) toxins; (34) exposure to solvents, PCBS, dry cleaning fumes, carbon monoxide; (34) extreme chilling; (35) eye muscle imbalance; (36) lesions; (37) continuous movement of the visual field past the eyes, i.e., looking from a moving train; (38) antihistamine use.[7] Administering the HGN

To administer the test correctly, the officer must do the following:

Preliminary qualifications -The entire test is administered by holding a stimulus (pen, finger) approximately 12-15 inches away from the subjects nose slightly above eye level[8]. Check for equal tracking, equal pupil size, resting nystagmus[9]. The officer does this by moving the stimulus across the person’s entire full line of vision. Although the manual does not give an exact amount of time, generally 1-2 seconds per eye is a fair speed. If the officer goes too fast, he cannot see if the eyes track, as eyes can only follow an object up to a certain speed. Three Steps of HGN

Step 1: Lack of smooth pursuit[10]

For all 3 steps, the officer will be checking each eye two times.

To check for lack of smooth pursuit, the officer moves the stimulus at a speed of two seconds from center position all the way to the side of the face. During this time, the officer is looking to see if the eye is able to pursue smoothly. Again, a nystagmus is an involuntary jerking of the eye. Many officers will testify that what they are looking for is similar to windshield wiper blades (as this example is in the training manual). If those wiper blades go across your windshield while it is wet, they will smoothly move. However, if the blades are old or the windshield is dry, the blades will jerk as they go back and forth[11].


Step 2: Distinct and sustained nystagmus at maximum deviation[12]

To do this, the officer moves the stimulus all the way to the side, so that no white is left showing in the corner eye. The officer then must hold the stimulus there for at least 4 seconds (but not longer than 30 seconds as this can cause fatigue nystagmus). The reason the officer must hold it that long, is because people will show a nystagmus at maximum deviation, even when unimpaired, for up to a few seconds[13].

This step is usually the one I can show the officer did incorrectly. Many officers forget about the sustained part (particularly if they use outdated training), and just move the pen all the way out.


Step 3: Onset prior to 45 degrees[14]

To do this step, the officer is trying to determine where a nystagmus is first present. The officer must move the stimulus at a rate that would take 4 seconds (so twice as long as LSP) to wherever the officer is guessing 45 degrees is. Once the officer sees the nystagmus, he is to hold the stimulus there to see if it remains.

To measure 45 degrees, the officer will usually say he went out 12-15 inches, which is the same distance he held the stimulus out. This angle will be 45 degrees, assuming his guess in inches is correct. Note however, this test is onset prior to 45 degrees. Many officers will make the mistake of saying they saw the nystagmus at 45 degrees. Further, some officers will say they measured 45 degrees by going out to the shoulder. However, everyone's shoulder width is different, so this does not sound like a very accurate method, to me at least. The manual states if no white is showing, the officer went too far, or the person has unusual eyes[15].

According to NHTSA, if the person has a nystagmus prior to 45 degrees, it is evident the BAC is above -0.08, as shown by research. (Whichresearch? I have no idea.)

Practice Tip: If it is evident that someone’s BAC is 0.08 or higher when there is onset prior to 45 degrees, you should argue it is evident the person’s BAC is less than 0.08 when there is no nystagmus prior to 45 degrees.

My belief, based upon other NHTSA research, and other actual scientific research, is that the NHTSA manual is false. According to Thorpes formula, BAC can be estimated as 50-angle of onset. So, at 45 degrees would be a 0.05, 44 degrees a 0.06, etc.

Further, look at the Robustness study. Get an expert, or hope you have an officer who likes to seem knowledgeable who took the time to read the study. The study is very favorable to the defense. It shows people have a nystagmus at as low as 0.02 BAC. The false positive rates are incredibly high. If you have an expert, I think you should argue Dahood should be revisited in light of this study showing just how inaccurate HGN is.

Practice Tip: In order to remember the timing, assuming the officer does the LSP first, it is 1-2 seconds for equal tracking, 2 for LSP, 4 seconds holding at maximum deviation, and 4 seconds to get to 45 degrees. So, the timing is 1,2,4,4. Scoring of HGN

If the officer observes 4 out of 6 clues, NHTSA research (according to the manual) shows 77% accuracy in determining a BAC above 0.10[16]

Each eye is checked twice, for the 3 separate clues. A clue can only be present for each step once per eye. So, while doing the LSP if the officer observes it twice in the left eye, and twice in the right eye, he can only count it once per eye. He would have noted 2 clues (1 for the left eye, and 1 for the right eye).


Practice Note - An odd number of clues will usually mean something is wrong. If a nystagmus is present in one eye, it should be present in the other. If it is not, one of two things likely happened. The officer either messed up and saw it when he shouldn't have, or didn't see it in the other eye when he should have. Or, the person has a medical condition (large disparity between the performance of the left and right eye may indicate a medical condition)[17].


9.5.3 Vertical Gaze Nystagmus (VGN)

This part of the test is optional, but often the officer will check for it.

To check for VGN, he basically does the distinct and sustained nystagmus, but goes up, instead of out to the side.

The officer is to take the stimulus, raise it so the eyes are elevated as far as possible, and hold it for approximately 4 seconds to see if jerking continues[18].

VGN is a sign of high BAC for that person (meaning someone with a high tolerance will take more alcohol to achieve), or a sign of impairment by drugs[19].



9.5.4 Walk and Turn


The second test that is typically administered is the Walk and Turn Procedures for Walk-and-Turn Testing Instructions

1. Instructions Stage: Initial Positioning and Verbal Instructions [21]

For standardization in the performance of this test, have the suspect assume the heel-to-toe stance by giving the following verbal instructions, accompanied by demonstrations:

"Place your left foot on the line” (real or imaginary). Demonstrate.

"Place your right foot on the line ahead of the left foot, with heel of right foot against toe of left foot." Demonstrate.

"Place your arms down at your sides." Demonstrate.

"Maintain this position until I have completed the instructions. Do not start to walk until told to do so."

"Do you understand the instructions so far?" (Make sure suspect indicates understanding.)


2. Demonstrations and Instructions for the Walking Stage[22]

Explain the test requirements, using the following verbal instructions, accompanied by demonstrations:

"When I tell you to start, take nine heel-to-toe steps, turn, and take nine heel-to-toe steps back." (Demonstrate 3 heel-to-toe steps.)

"When you turn, keep the front foot on the line, and turn by taking a series of small steps with the other foot, like this." (Demonstrate).

"While you are walking, keep your arms at your sides, watch your feet at all times, and count your steps out loud."

"Once you start walking, don't stop until you have completed the test."

"Do you understand the instructions?" (Make sure suspect understands.)

"Begin, and count your first step from the heel-to-toe position as 'One.'" Test Interpretation[23]

“You may observe a number of different behaviors when a suspect performs this test. Original research demonstrated that the behaviors listed below are likely to be observed in someone with a BAC above 0.10. Look for the following clues each time this test is given:


A. Cannot keep balance while listening to the instructions. Two tasks are required at the beginning of this test. The suspect must balance heel-to-toe on the line, and at the same time, listen carefully to the instructions.

Typically, the person who is impaired can do only one of these things. The suspect may listen to the instructions, but not keep balance. Record this clue if the suspect does not maintain the heel-to-toe position throughout the instructions. (Feet must actually break apart.) Do not record this clue if the suspect sways or uses the arms to balance but maintains the heel-to-toe position.

B. Starts before the instructions are finished. The impaired person may also keep balance, but not listen to the instructions. Since you specifically instructed the suspect not to start walking "until I tell you to begin," record this clue if the suspect does not wait.

C. Stops while walking. The suspect pauses for several seconds. Do not record this clue if the suspect is merely walking slowly.

D. Does not touch heel-to-toe. The suspect leaves a space of more than one-half inch between the heel and toe on any step.

E. Steps off the line. The suspect steps so that one foot is entirely off the line.

F. Uses arms to balance. The suspect raises one or both arms more than 6 inches from the sides in order to maintain balance.

G. Improper turn. The suspect removes the front foot from the line while turning. Also record this clue if the suspect has not followed directions as demonstrated, i.e., spins or pivots around.

H. Incorrect number of steps. Record this clue if the suspect takes more or fewer than nine steps in either direction.

Note: If suspect can't do the test, record observed clues and document the reason for not completing the test, e.g. suspect’s safety.

If the suspect has difficulty with the test (for example, steps off the line), continue from that point, not from the beginning. This test may lose its sensitivity if it is repeated several times.

Observe the suspect from a safe distance and limit your movement which may distract the suspect during the test. Always consider officer safety. Scoring[24]

“Based on original research, if the suspect exhibits two or more clues on this test or fails to complete it, classify the suspect's BAC as above 0.10. Using this criterion, you will be able to accurately classify 68% of your suspects.” So, 2 clues out of 8 is a failure. Test Conditions[25]

“Walk-and-Turn test requires a designated straight line, and should be conducted on a reasonably dry, hard, level, nonslippery surface. There should be sufficient room for suspects to complete nine heel-to-toe steps. Note: Recent field validation studies have indicated that varying environmental conditions have not affected a suspect’s ability to perform this test.”


9.5.5 One Leg Stand Procedures for One-Leg Stand Testing[26]

“1. Instructions Stage: Initial Positioning and Verbal Instructions

Initiate the test by giving the following verbal instructions, accompanied by demonstrations.

"Please stand with your feet together and your arms down at the sides, like this." (Demonstrate)

"Do not start to perform the test until I tell you to do so."

"Do you understand the instructions so far?" (Make sure suspect indicates understanding.)

2. Demonstrations and Instructions for the Balance and Counting Stage

Explain the test requirements, using the following verbal instructions, accompanied by demonstrations:

"When I tell you to start, raise one leg, either leg, with the foot approximately six inches off the ground, keeping your raised foot parallel to the ground.” (Demonstrate one leg stance.)

"You must keep both legs straight, arms at your side.”

"While holding that position, count out loud in the following manner: “one thousand and one, one thousand and two, one thousand and three, until told to stop.” (Demonstrate a count, as follows: "one thousand and one, one thousand and two, one thousand and three, etc." Officer should not look at his foot when conducting the demonstration - OFFICER SAFETY.)

"Keep your arms at your sides at all times and keep watching the raised foot."

"Do you understand?" (Make sure suspect indicates understanding.)

"Go ahead and perform the test." (Officer should always time the 30 seconds. Test should be discontinued after 30 seconds.)

Observe the suspect from a safe distance. If the suspect puts the foot down, give instructions to pick the foot up again and continue counting from the point at which the foot touched the ground. If the suspect counts very slowly, terminate the test after 30 seconds.” Test Interpretation[27]

“You may observe a number of different behaviors when a suspect performs this test. The original research found the behaviors listed below are the most likely to be observed in someone with a BAC above 0.10. Look for the following clues each time the One-Leg Stand test is administered.

A. The suspect sways while balancing. This refers to side-to-side or back-and- forth motion while the suspect maintains the one-leg stand position.

B. Uses arms for balance. Suspect moves arms 6 or more inches from the side of the body in order to keep balance.

C. Hopping. Suspect is able to keep one foot off the ground, but resorts to hopping in order to maintain balance.

D. Puts foot down. The suspect is not able to maintain the one-leg stand position, putting the foot down one or more times during the 30-second count.

Note: If suspect can't do the test, record observed clues and document the reason for not completing the test, e.g. suspect’s safety.

Remember that time is critical in this test. The original research has shown a person with a BAC above 0.10 can maintain balance for up to 25 seconds, but seldom as long as 30. Scoring

Based on original research, if an individual shows two or more clues or fails to complete the One-Leg Stand, there is a good chance the BAC is above 0.10”[28]. (So, two clues out of four would classify the driver as a failure).

“Using that criterion, you will accurately classify 65% of the people you test as to whether their BAC's are above 0.10.

Observe the suspect from a safe distance and remain as motionless as possible during the test so as not to interfere. If the suspect puts the foot down, give instructions to pick the foot up again and continue counting from the point at which the foot touched the ground. If the suspect counts very slowly, terminate the test after 30 seconds”[29]. Test Conditions[30]

“One-Leg Stand requires a reasonably dry, hard, level, and non-slippery surface. Suspect's safety should be considered at all times.”

“The original research indicated that certain individuals over 65 years of age, back, leg or inner ear problems, or people who are overweight by 50 or more pounds had difficulty performing this test. Individuals wearing heels more than 2 inches high should be given the opportunity to remove their shoes.”

[1]Id. at VIII-4

[2]Id. at VII-3



[5]Id. at VIII-4

[6]State v. Dahood, 148 NH 723,729 (2002)

[7]Schultz v. State, 106 Md. App. 145 (1995)

[8] Student Manual 2006 at VIII-6

[9]Id. at VIII-9

[10]Id. at VIII-7

[11]Id. at VIII-5

[12]Id at VIII-7

[13]Id. at VIII-5

[14]Id. at VIII-7

[15]Id. at VIII-7

[16]Id at VIII-3

[17]Id at VIII-8

[18]Id at VIII-8


[20]Images from NHTSA, in public domain.

[21]Id at VIII-9


[23]Id at VIII-10

[24]Id at VIII-11

[25]Id at VIII-11

[26]Id at VIII-12

[27]Id at VIII-13



[30]Id. at VIII-13


It is important to note these tests are "standardized" tests. The officer cannot and should not deviate from the training or scoring. The manual emphasizes this in capital letters and in bold:







A majority of the State's case will likely be the field sobriety tests. If the tests are not administered, you should emphasize they are voluntary (prior to arrest. After arrest, they are arguably physical tests and the implied consent statute applies).

It is important to note the tests DO NOT DIRECTLY MEASURE IMPAIRMENT. There were originally validated to detect a BAC above 0.10[1], and then through a validation study of 0.08 (NHTSA often changes the numbers, so carefully read the underlying studies).

While the validation studies, according to NHTSA support the accuracy of the tests, the studies have numerous flaws, which are discussed further in this chapter.

Finally, if you look at the false positives, in some cases it is more than 50%.