Field Sobriety Tests in Massachusetts

What Are Field Sobriety Tests?

Field sobriety tests are physical and cognitive tasks that a police officer asks a driver to perform during a traffic stop. Officers use the results to help them decide whether there is probable cause to arrest someone for operating under the influence.

In Massachusetts, police typically use five main tests to evaluate impairment:

These tests are designed to detect physical or mental signs of impairment. They are not meant to confuse or trick a person—but factors like nerves, medical conditions, uneven pavement, and poor weather can all affect performance.

NHTSA-Approved vs. Non-Approved Tests

The National Highway Traffic Safety Administration (NHTSA) has established scientific standards for field sobriety testing. However, only three of the five common tests have been validated by the NHTSA:

The alphabet test and finger-to-nose test do not meet NHTSA standards. A skilled defense attorney can argue that results from non-validated tests should carry little or no weight as evidence, since they haven’t been scientifically proven to accurately indicate impairment.

Even the NHTSA-approved tests must be administered exactly according to protocol. Deviations in instructions, demonstration, scoring, or environmental conditions can render results unreliable.

Landmark Massachusetts Case Law

Massachusetts has unique case law that significantly impacts how field sobriety test evidence can be used in court. Two landmark decisions provide critical protections for defendants:

Commonwealth v. Sands (1997)

The Massachusetts Supreme Judicial Court ruled that the Horizontal Gaze Nystagmus (HGN) test cannot be admitted as evidence unless its reliability is thoroughly established and the officer administering it is duly qualified. This creates a high evidentiary bar—prosecutors must prove the test was properly administered by a trained officer before results can be considered.

Together, these cases mean that police must meticulously follow established guidelines for FSTs to qualify as reliable evidence, and your refusal to participate cannot be held against you.

How an Attorney Can Challenge FST Evidence

An experienced OUI defense attorney will scrutinize every aspect of how field sobriety tests were conducted. Common challenges include:

• Improper administration — Officer failed to follow NHTSA standardized procedures
• Environmental factors — Uneven pavement, poor lighting, inclement weather, or heavy traffic conditions
• Medical conditions — Inner ear disorders, leg injuries, neurological conditions, or medications can mimic impairment
• Non-validated tests — Alphabet and finger-to-nose tests lack scientific backing
• Officer qualifications — Insufficient training in NHTSA-standardized testing methods
• Age, weight, or physical limitations — These factors can significantly affect test performance without any impairment

If an officer testifies about a non-approved test, a knowledgeable attorney can object and seek to have that evidence excluded. Where officers deviated from NHTSA protocols, the attorney can argue the results are invalid.