Field Sobriety Tests in Rhode Island DUI Cases: Validity, Challenges & Defenses

Updated June 2026 by Matthew T. Marin, Esq. (NCDD member, Super Lawyers 2014+, landmark wins in State v. Corcoran (2022)) and Stefanie A. Murphy, Esq. (lead author of A Practical Guide to Trying DUI Cases in RI, 2nd Ed., RI Police Academy lecturer on DUI defense).

When analyzing a Police Officer’s report, one of the first areas that a skilled Rhode Island DUI Lawyer will review is the Officer’s description of the field sobriety testing. We know from our experience that “field sobriety tests” are not automatically reliable simply because a Police Officer flatly states that the tests were administered and that the operator failed the tests. To begin, the Field Sobriety Tests are “standardized” through intense research and development by the National Highway Traffic Safety Administration. The “standardization” of the process is one of the fundamental building blocks of the tests upon which the reliability of the tests is built.

How a Skilled Rhode Island DUI Lawyer Can Spot an Inexperienced DUI Investigator

As an experienced Rhode Island DUI Lawyer, we have read literally thousands of DUI police reports and can instantly spot an inexperienced DUI investigator. They can typically be identified by one of two methods. First, it is possible that their description of the standardized field sobriety testing is extremely short. Recently, I reviewed a report by a rookie Officer in which the description of each test was one or two sentences each. This is simply not enough information to document and detail both the administration of the testing as well as the Officer’s observations of the operator’s performance on the test.

This is key because in most cases a trial in a DUI case may not take place for two or three months after the initial arrest. In that intervening time it is likely that the Officer will undertake dozens of additional investigations and, when the time for trial arrives, he will no longer be able to recount the important observations that he failed to include in his police report. Moreover, if he does recount important observations that he failed to include in his police report this can lead to a very effective cross examination and draw doubt as to the validity or truthfulness of those observations.

The second method of detecting an inexperienced DUI investigator is that the description of the field sobriety testing is literally copied and pasted from another report. Some ways we can detect if this is occurring is by the language used in the report; she is used intermittently instead of he, the operator is identified by the wrong name, described as daytime instead of nighttime, and other inexplicable inaccuracies that are likely due to a failure to review the report instead of a genuine error in preparing the report.

Field Sobriety Tests as “Probable Cause” to Arrest

As we indicated above, one of the critical reasons that field sobriety tests are administered is to establish “probable cause” to place a suspect under arrest for suspicion of driving under the influence. Probable cause is generally defined as “circumstances and facts which give rise to a reasonable belief that an accused is guilty of a crime.” This is a much lower standard than “proof beyond a reasonable doubt” and is generally satisfied by a showing of proper administration and alleged failure of the standardized field sobriety tests. This low standard is difficult to defeat by the defense, but there are some ways in which it can be done. Typically, the defense can file a Motion to Suppress the standardized field sobriety tests because they are unreliable and should not be admitted into evidence. The defense would argue that the tests are unreliable due to the fact that they were not administered and performed in the required standardized manner. In egregious cases, the Court may prevent the prosecution from admitting such evidence.

Field Sobriety Tests as “Proof Beyond a Reasonable Doubt”

If the prosecution can meet its burden and establish that the arresting Officer had probable cause to arrest the operator for driving under the influence, the field sobriety tests continue to play an important role in the case moving forward. If the operator submitted to a chemical test and the prosecution plans on introducing those results into evidence against the operator, the field sobriety tests play a lesser or secondary role as “other supporting evidence.”

If, however, the operator refused to submit to a chemical test, the field sobriety tests are THE critical aspect of the case that the entire prosecution relies upon. In a DUI case in which the prosecution cannot introduce evidence of the operator’s blood alcohol content, the field sobriety tests constitute the only scientific evidence of the operator’s guilt. In this situation, having a skilled and experienced Rhode Island DUI Defense lawyer on your side can mean the difference between guilty and not guilty. We have had a great deal of success derailing the testimony of DUI investigators using our knowledge of the field sobriety tests to exploit errors or weaknesses in the administration and evaluation of the tests. Some of the ways we attack the field sobriety tests include:

• Arguing that the tests were not performed in the standardized manner as required;
• Pointing out that the arresting Officer was not properly trained or certified to administer the tests;
• Discrediting the scientific underpinnings of the reliability of the field sobriety test;
• Arguing that our Client, contrary to the Officer’s conclusion, actually passed the field sobriety test;
• Arguing that the Client was not physically able to perform the field sobriety test;
• Arguing that the tests were administered in an unsafe area or in poor weather conditions;

What are the Standardized Field Sobriety Tests?

All Rhode Island Police Officers who are trained to investigate DUI cases are trained to administer a battery of three standardized field sobriety tests. These tests were developed through research conducted by the National Highway Traffic Safety Administration and a manual was created to teach these tests to Police. We have extensive knowledge of the policies and procedures as explained by the National Highway Traffic Safety Administration manual, oftentimes a better working knowledge than the officers we cross-examine.

Horizontal Gaze Nystagmus Test

The Horizontal Gaze Nystagmus test, also commonly referred to as the HGN, is a test that is performed on a suspected drunk driver’s eyes. There are a number of different observations that the administering officer is trained to look for. In layman’s terms, the Officer is looking for an involuntary jerking of the eye, which scientific research has concluded indicates that a suspect’s blood alcohol content is 0.10 or greater. Unfortunately, this is an observation that can only be made by the individual administering the test, and the subject cannot tell whether they pass or fail the test. Only the Officer can see the involuntary jerking of the eye. However, since the validity and reliability of this test rely upon complex scientific underpinnings, it is usually a good area for extensive cross-examination to expose the Officer’s lack of deep understanding of the test or the conclusions that can be drawn from the test.

Walk and Turn Test

The Walk and Turn Test, also commonly referred to as the Nine Step Walk and Turn Test, is a memory, coordination, and balance test. The test requires a suspect to stand in a starting position, right foot in front of the left heel to toe. From that position, the suspect must take nine steps out on a line in a heel-to-toe manner while keeping their arms by their sides. After the ninth step, the suspect must make a turn using a series of small steps and walk back nine steps in a heel-to-toe fashion on the line as instructed. This test is extremely difficult to perform successfully. There are a total of eight different observations that an officer is trained to look for while a suspect is performing this test. If the officer observes two or more, he can conclude that the test is indicative of operator impairment. The eight observations the officer is looking for are:

1. Failing to maintain the starting position;
2. Starting the test before instructed;
3. Stepping off the line;
4. Taking the wrong number of steps;
5. Raising arms for balance;
6. Improper turn;
7. Missing heel to toe on one or more steps;
8. Stops walking while performing the test;

One Leg Stand Test

The final test in the battery of standardized field sobriety testing is known as the one leg stand test. In this test, the officer instructs the subject to raise one foot 6 inches off the ground and point the toe out. With the foot raised, the suspect is instructed to count one thousand one, one thousand two… until he is instructed to stop. The officer is to keep an independent timeline and conclude the test after thirty seconds have elapsed. There are four different observations that the officer is trained to watch for on this test and two of the four observations allow the officer to draw the conclusion that the operator is under the influence. The four observations on this test are:

1. Placing the foot down after beginning;
2. Hopping in place;
3. Swaying while balancing;
4. Raising arms for balance;

Attacking the Standardized Field Sobriety Tests

Attacking the standardized field sobriety tests is critical to the defense of any DUI charge. In Rhode Island, the standardized field sobriety evidence is a substantial part of the prosecution’s DUI case, and having a skilled and experienced Rhode Island DUI Lawyer assisting you, evaluating the evidence, and cross-examining the Police involved is essential. We have read, handled, and fought hundreds of Rhode Island DUI cases. Let us put our experience and knowledge to work for you.

Protect Your Rights with Skilled DUI Defense

In conclusion, field sobriety tests play a crucial role in Rhode Island DUI cases, but they are not infallible. A knowledgeable and experienced Rhode Island DUI defense attorney can challenge the administration and reliability of these tests to protect your rights. If you are facing DUI charges, don’t leave your future to chance. Contact the Marin & Murphy Law Firm today at (401) 228-8271 for a free consultation, and let us build a strong defense on your behalf.

Meet Our Experienced Rhode Island DUI Defense Attorneys

MATTHEW T. MARIN, ESQ.

PARTNER

• Successfully argued for suppression of breath test results in landmark 2015 Rhode Island District Court cases (including State v. Zimmerman), challenging the adequacy of the state’s DUI Rights for Motorists form— leading to multiple judicial rulings finding the form misleading and ultimately prompting the Rhode Island Attorney General’s Office to revise the form statewide to better inform motorists of their rights under amended DUI laws
• Through a firm associate, successfully argued and prevailed in the Rhode Island Supreme Court case
  State v. Corcoran (R.I. 2022), affirming the suppression of incriminating statements in a DUI investigation—establishing key precedent that roadside questioning after a collision and failed sobriety tests constitutes custodial interrogation requiring Miranda warnings, significantly strengthening protections for defendants in impaired driving cases statewide. Successfully argued by Attorney Marin in the Washington County Superior Court.
• Member of the prestigious National College for DUI Defense (NCDD)
• Handled thousands of DUI cases, focusing on breath, blood, and urine test challenges
• Selected to Super Lawyers every year since 2014 | National Trial Lawyers Top 100
• Avvo Rating: 10.0 “Superb” | Martindale-Hubbell: AV Preeminent
• Featured in Rhode Island Bar Journal articles on DUI defense strategies
• Admitted to the Rhode Island Supreme Court (2008) and U.S. District Court for Rhode Island
• Deep expertise in 2025 RI DUI law changes, including the expanded 10-year look-back period

Learn more about Matthew T. Marin →

STEFANIE A. MURPHY, ESQ.

PARTNER

• Lead editor and contributing author of the authoritative
  A Practical Guide to Trying DUI Cases in Rhode Island
  (2nd Edition 2024, MCLE New England), a comprehensive legal resource offering in-depth analysis, practical guidance, current case law, statutory authorities, sample pleadings, checklists, and proven strategies for defending and prosecuting DUI cases in Rhode Island—essential for attorneys navigating complex drunk driving litigation in the state
• Invited by the Rhode Island Municipal Police Training Academy to lecture and demonstrate DUI trial practice and defense strategies to incoming municipal police recruits—sharing in-depth knowledge of Rhode Island DUI prosecution and defense tactics with future law enforcement officers statewide, underscoring her recognized expertise in impaired driving litigation
• Extensive courtroom experience defending DUI and serious criminal charges including Second Offense DUI Charges and Felony DUI Charges
• Focus on achieving charge dismissals and reductions for clients
• Avvo Rating: 10.0 | Martindale-Hubbell Peer Rating: 4.6/5.0
• Recognized for outstanding results across a broad spectrum of criminal cases
• Expertise in 2025 RI DUI law updates and aggressive trial representation
• Advanced training in criminal defense and DUI litigation
• Admitted to the Rhode Island Supreme Court (2004) and U.S. District Court for Rhode Island

Learn more about Stefanie A. Murphy →