The stop itself is the foundation of every OUI case, and it is often the first place a defense attorney looks for vulnerabilities.
In order for a traffic stop to be constitutional, the officer must have had a reasonable articulable suspicion that a traffic law was being violated or that criminal activity was occurring. This is a relatively low legal standard, but it is not zero — it requires something specific and objective, not merely a hunch.
If the stop was made without sufficient justification, the evidence gathered as a result — the officer’s observations, the field sobriety test results, the breathalyzer result — may be suppressible under the Fourth Amendment of the United States Constitution and Article Fourteen of the Massachusetts Declaration of Rights. A successful motion to suppress the stop can reduce the prosecution’s case to nothing.
Field Sobriety Tests: What You May Not Know
Field sobriety tests are the next major element of most OUI cases, and they deserve detailed attention because they are widely misunderstood.
The three standardized field sobriety tests recognized by the National Highway Traffic Safety Administration are:
- The Horizontal Gaze Nystagmus (HGN) test — tracking an object with the eyes to detect involuntary eye movement associated with impairment
- The Walk and Turn test — walking a line, turning, and walking back while following specific instructions
- The One Leg Stand test — standing on one leg for a specified period
These tests were developed based on scientific research and are intended to be administered in accordance with specific, validated protocols. When they are administered correctly and under appropriate conditions, they have some ability to detect impairment. When they are administered incorrectly, or under conditions that invalidate the testing environment — uneven pavement, poor lighting, a subject with medical conditions that affect balance, or instructions delivered improperly — their results are unreliable.
You Do Not Have to Perform Field Sobriety Tests in Massachusetts
Here is something critically important that many people don’t know: you are not legally required to perform field sobriety tests in Massachusetts. Unlike the chemical test (which carries an implied consent obligation discussed below), field sobriety tests are voluntary. Politely declining to perform field sobriety tests cannot be used against you at trial in Massachusetts.
Many attorneys advise clients that declining field sobriety tests is often the prudent course — not because performance on these tests proves innocence, but because poor performance, even by a completely sober person, can be used to build the government’s case.
How We Challenge Field Sobriety Tests
As specialized OUI defense attorneys, we scrutinize every field sobriety test administration carefully. We examine:
- The conditions under which the tests were given
- Whether the officer followed NHTSA-prescribed instructions precisely
- Whether the subject had medical conditions, environmental factors, footwear issues, or other factors that would affect performance
- Whether the officer’s documentation of the results accurately reflects what actually happened
Errors in field sobriety test administration are common, and those errors can significantly undermine the government’s case.
The Breathalyzer: Science, Vulnerabilities, and a Landmark Massachusetts Case
The breathalyzer is the other major piece of evidence in most OUI cases, and it is an area where the technical complexity of OUI defense becomes very clear.
Massachusetts currently uses the Draeger Alcotest 9510 breathalyzer. This device measures the concentration of alcohol in a breath sample and converts it mathematically to a projected blood alcohol content. The machine operates on assumptions — about body temperature, about the ratio of breath alcohol to blood alcohol, about the absence of certain substances in the subject’s system that could produce false positives — and any one of those assumptions can be wrong in a given individual.
Milligan & Higgins is a premier OUI and criminal defense firm in Massachusetts, with over forty years of collective experience. If you or a loved one is facing criminal charges, we are here to help.
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Contact Milligan & Higgins for a free consultation or second opinion. Please send us an email: Intake@milliganhiggins.com or call 781-878-1231.
