Massachusetts Field Sobriety Test FAQs

An officer may direct roadside field sobriety exercises when the officer has reasonable suspicion of OUI based on specific and articulable facts. In Commonwealth v. Blais, 428 Mass. 294, 297-302 & n.3 (1998), the Supreme Judicial Court held that the exercises are a reasonable part of a lawful investigative detention. Police do not need the driver’s consent and do not need to give a warning about a right to refuse the exercises. The defense may ask the judge to suppress observations that police obtained by extending the stop for the exercises if the officer lacked reasonable suspicion.

Refusing the roadside field sobriety exercises does not cause the automatic license suspension that the Registry imposes for refusing the breathalyzer. In Commonwealth v. McGrail, 419 Mass. 774, 779-780 (1995), the Supreme Judicial Court held that an actual refusal to perform the exercises is testimonial and generally inadmissible under Article 12 of the Massachusetts Declaration of Rights. The judge may, however, permit limited refusal evidence if the defense creates a misleading impression of complete cooperation or suggests that police never offered the exercises. The purpose of that limited evidence is to correct the misleading impression. Statements or conduct during an attempted exercise are analyzed separately from a refusal.

No. The lawful authority to direct field sobriety exercises does not authorize police to use physical force to make a driver perform them. The Supreme Judicial Court made the limit on physical force explicit in Commonwealth v. Blais. Police threats, actual force, or restraints that exceed the needs of a lawful investigative detention may support a separate motion to suppress. The judge’s decision on the motion to suppress depends on the officer’s words and conduct, whether reasonable suspicion supported the direction, the length and setting of the detention, and the complete circumstances surrounding the attempted administration.

Not automatically. In Commonwealth v. Blais, the Supreme Judicial Court held that consent is unnecessary during a lawful detention supported by reasonable suspicion. Therefore, a judge does not exclude the evidence only because the officer used the word mandatory. The judge weighs the officer’s statement that the exercises were mandatory when police lacked reasonable suspicion and the Commonwealth relies on voluntary consent, or when threats, force, or the surrounding circumstances exceeded lawful investigative authority. The judge evaluates the legal basis for the officer’s direction and the interaction between the officer and the driver. A misleading statement about mandatory performance may support suppression in the proper case, but Massachusetts courts have not adopted an automatic exclusion rule based only on the word mandatory.

The standardized exercises are structured observations, not chemical measurements of alcohol concentration. The National Highway Traffic Safety Administration developed the three-exercise battery to help an officer classify whether a person’s alcohol concentration was likely at or above a specified level. The battery does not measure the person’s actual alcohol concentration or directly measure driving ability. Massachusetts courts generally permit testimony about observed performance as lay evidence. An officer’s departure from the prescribed procedure may mean that the validation research does not support the officer’s conclusions. A judge does not, however, automatically exclude the observations whenever an officer departs from the procedure. Horizontal gaze nystagmus evidence is subject to a separate rule that requires a scientific foundation.

The standardized battery consists of horizontal gaze nystagmus, the walk and turn, and the one leg stand. The National Highway Traffic Safety Administration prescribes instructions, demonstrations, test conditions, and clue definitions for each exercise. The officer should follow the prescribed procedures before relying on the validation associated with the battery. The defense compares the instructions, surface, timing, scoring, report, testimony, and available video with the prescribed procedure. A difference between the officer’s administration and the prescribed procedure may affect admissibility in a particular case, the foundation of an opinion, or the weight the judge or jury gives the observations.

In the walk and turn and the one leg stand, the officer asks a person to remember instructions while performing an unfamiliar physical task. Officers describe these exercises as divided-attention testing because driving also requires a person to process information while controlling movement. Anxiety, fatigue, weather, passing traffic, cruiser lights, unfamiliar instructions, and the stress of a possible arrest can divide a sober person’s attention. The officer also lacks a sober baseline showing how that particular driver would perform the same exercise under comparable roadside conditions.

The officer scores eight clues. Losing balance during instructions and beginning too soon are two clues that can arise before the first step. The remaining clues are stopping while walking, missing heel to toe by more than the prescribed distance, stepping off the line, using the arms for balance, making an improper turn, and taking the wrong number of steps. The procedure calls for a designated straight line and a specific nine-step sequence in each direction. The defense compares each claimed clue with the video. The defense also notes any correct performance that the police report may omit.

The officer scores four clues during approximately 30 seconds. The clues are swaying, using the arms for balance, hopping, and putting the foot down. The officer instructs the person to raise one foot about six inches, keep both legs straight, point the raised foot forward, watch it, and count aloud. A momentary foot touch does not end the exercise. The officer tells the person to raise the foot and continue. The officer must still distinguish a scored event from an ordinary balance adjustment and account for the surface, conditions, footwear, and the driver’s physical circumstances.

Horizontal gaze nystagmus is an involuntary jerking of the eyes. The officer moves a stimulus while looking for eye movements, using prescribed distances, speeds, positions, and hold times. Massachusetts courts treat the result of the horizontal gaze nystagmus test as scientific evidence. In Commonwealth v. Sands, 424 Mass. 184 (1997), the Supreme Judicial Court required a foundation addressing the scientific proposition, the witness’s qualifications, and the procedure used. A police report that lists HGN clues does not establish admissibility. Video may also reveal rushed passes, inconsistent positioning, or an incomplete medical screen.

Yes. Officers may use alphabet recitation, backward counting, a finger count, Modified Romberg, or finger to nose. These exercises are not part of the validated three-test standardized field sobriety battery. The National Highway Traffic Safety Administration prescribes administration procedures for Modified Romberg and finger to nose in its drug-recognition curriculum. The agency recognizes, however, that those exercises have not received the same controlled validation as the standardized alcohol battery. The defense examines the actual instructions, the officer’s training, what the officer treated as significant, and whether the officer testifies to an unsupported scientific conclusion drawn from a simple observation.

In an alcohol-OUI case, an officer may describe the driver’s balance, coordination, instruction-following, and other performance. The officer may also give a lay opinion about sobriety or intoxication, but may not answer the ultimate legal question whether alcohol diminished the person’s ability to operate safely. In Commonwealth v. Gerhardt, 477 Mass. 775 (2017), the Supreme Judicial Court required the neutral term roadside assessments for the exercises in a marijuana-OUI case. A lay officer may not say that the person passed or failed, that the performance established marijuana impairment, or that the person was intoxicated by marijuana. The driver’s performance on the roadside assessments alone is insufficient to prove the charge.

Age, weight, fatigue, anxiety, injuries, back or leg conditions, inner-ear conditions, footwear, wind, cold, lighting, passing traffic, cruiser lights, and an uneven or slippery surface can affect balance, coordination, and concentration. Language and unfamiliar instructions can also affect performance. The judge does not automatically exclude the observations because of these conditions. The judge or jury considers those conditions in deciding whether the officer followed the training and how much weight to give a claimed clue. The officer ordinarily has no sober baseline showing how that driver performs the same exercise in comparable conditions.

Video can show whether the surface was level, whether a line was visible, how the officer explained and demonstrated the exercise, how long the person stood or walked, and which movements actually occurred. The video may confirm the police report, reveal a scoring error, or show successful performance that the report omitted. The video may also fail to show a foot, an eye movement, or a small distance because of the camera angle. Video evidence is therefore not automatically conclusive. Defense counsel compares the recording with the police report, the testimony, and the prescribed procedure instead of relying on a summary that the driver performed poorly.

Defense counsel begins the review with the stop and with whether specific facts supported the request for roadside exercises. Counsel then compares the officer’s instructions, demonstrations, conditions, timing, scoring, report, testimony, training materials, and available video. The defense identifies correct performance as well as claimed clues and separates protected refusal evidence from statements or conduct during an attempted exercise. Attorney Serpa explains the trial method in the firm’s article on cross-examining a field sobriety opinion. The broader criminal framework appears on the Massachusetts OUI defense page.