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Standardized Field Sobriety Testing


Standardized field sobriety tests (SFSTs) are roadside tests police conduct during a traffic stop in Maine to determine if a driver is impaired or unlawfully under the influence of alcohol or drugs. The National Highway Traffic Safety Administration (NHTSA) has developed three standardized field sobriety tests, which have been adopted by law enforcement in Maine. The three tests are (1) the Horizontal Gaze Nystagmus (HGN) test, (2) the walk-and-turn test, and (3) the one-leg-stand test.

At the Law Offices of Dylan Boyd, our OUI defense lawyers explain what you should know about field sobriety testing in Maine and how these tests can be challenged. We believe informed clients make better decisions about their OUI cases. Contact us today at (207) 536-7147 to schedule a consultation.

5 Ways to Challenge Field Sobriety Tests in Maine

If you took a field sobriety test and were subsequently arrested, you should consult a qualified OUI attorney to evaluate whether your tests should be challenged. These test results can be used against you in court and at the Bureau of Motor Vehicles (BMV), potentially resulting in criminal penalties, including imprisonment, and suspension of your driver's license. The strategy used to challenge these tests depends on the facts and circumstances of your case.

  1. Did the officer administer the tests improperly or fail to provide adequate instructions? We will review any audio or video as well as speak to you and other witnesses.
  2. Did the road, traffic, or weather conditions impact performance? We can review videos, photographs, weather reports, traffic reports, and other forms of evidence.
  3. Did your shoes, clothing, or health condition impact performance? We will review these issues with you.
  4. Was the officer's subjective assessment flawed? We will again review any videos or police reports and consider if the allegations are valid.
  5. Were your constitutional rights violated? You have certain rights, and if the police violated any of these rights, evidence obtained as a result of the violation could be suppressed (excluded) from evidence.

It is critical to speak to a qualified OUI defense lawyer in Maine to understand what your rights are and how best to fight the criminal charge and license suspension.

Horizontal Gaze Nystagmus (HGN)

The HGN test is one of three SFSTs validated by NHTSA and used by Maine police officers during OUI stops to help determine whether a driver is under the unlawful influence of alcohol or drugs. However, this test is not always reliable, and there may be grounds for objecting to its admission as evidence.

The officer conducting the HGN test should provide clear verbal instructions to the driver. The police officer should tell the driver to stand still, place hands to the side, and keep the head still. Then they must be properly instructed to look at a stimulus, like a pen or another object, and follow it with both eyes while the officer moves the stimulus from right to left.

The officer assesses the driver's eyes while moving the object from side to side. HGN tests, however, are very technical in their application. Proper administration involves specific requirements on distance between the stimulus and the driver's nose, timing and length of holds, and how many times and ways the stimulus is passed back and forth.

The HGN test is meant to measure the involuntary jerking of the eye--known as "nystagmus." A driver with a high blood alcohol concentration may exhibit involuntary jerking of an eye as the driver gazes toward the side while following the stimulus.

3 Clues of Intoxication

Police look for three major clues while administering the HGN test. Each eye is assessed for these three clues, so there are actually a total of six possible indicators of intoxication--one for each eye. If the officer determines four or more clues exist, that is supposed to indicate the driver's blood alcohol content (BAC) level is above the 0.08 percent legal limit.

  1. Clue 1 ("lack of smooth pursuit") occurs when the driver is unable to follow the stimulus as it moves back and forth without demonstrating nystagmus.
  2. Clue 2 ("distinct and sustained nystagmus at maximum deviation") involves nystagmus when the eye gazes as far as possible to the right or left, with the officer looking for sustained and distinct jerking of the eyes when they are focused to the side.
  3. Clue 3 ("onset of nystagmus prior to 45 degrees") involves the onset of nystagmus before 45 degrees between the center of the eyes and peripheral vision.

Each clue requires specific motions or manners in which the stimulus is held or passed. Each clue also requires different timing. 

Ways to Challenge the HGN Test in Maine

HGN tests can be challenged effectively by arguing against their reliability (these tests are highly subjective) or proving improper administration of the test (these tests require following strict and specific technical rules). Also, these tests can be challenged based on matters not associated with the test itself, but matters related to the driver or to the environment.

Common Challenges to the HGN Test

  • Unreliable based on police officer's subjective estimations and preconceived notions
  • Unreliable based on police officer's failure to administer the test properly
  • Unreliable based on external factors (e.g., lighting conditions, medical conditions)

The HGN test may be faulty. Your OUI defense attorney should be able to highlight these weaknesses and create reasonable doubt in the prosecution's case against you. Our OUI defense lawyers will investigate and review the results of your HGN test and challenge it accordingly. Contact us online or at (207) 536-7147 to schedule a consultation and learn more about how we will help you fight your Maine OUI charge.

The Walk-and-Turn Test

The walk-and-turn test is a SFST typically used by police in Maine to determine whether a driver is unlawfully under the influence of drugs or alcohol. This test is what is known as a "divided attention test": the police get you to shift conscious attention from one task (standing without staggering) and another task (listening to instructions).

During the walk-and-turn test, the police are supposed to provide clear instructions and demonstrate the task before you begin the test. The test itself involves walking in a straight line, heel-to-toe, for approximately nine steps with your arms at your side. Then, at the conclusion of the nine steps, you turn around, in a certain way, and walk back to the starting point in the same heel-to-toe manner.

The NHTSA requires certain conditions in order for the test to be performed properly:

  1. A designated straight line;
  2. A reasonably dry, hard, level non-slippery surface;
  3. Adequate room for nine steps; and
  4. An option to remove shoes with heels two inches high.

The walk-and-turn test consists of eight clues:

  1. Lack of balance while following instructions;
  2. Beginning before instructed to begin;
  3. Failing to touch your heel to your toe while walking;
  4. Stepping off of the straight line;
  5. Stopping while walking;
  6. Raising or moving arms to maintain balance;
  7. Making an improper turn; and
  8. Taking more or fewer than nine steps.

Missing or failing two or more clues is supposed to indicate that your blood alcohol content (BAC) level is likely over the 0.08 percent legal limit. However, the walk-and-turn test is flawed, and the results may be subject to legal attack. The walk-and-turn test is not a reliable way to determine unlawful intoxication. Problems often involve how the test is administered, pre-existing physical or mental conditions, and unsatisfactory environmental conditions. In addition, the police make mistakes. They may not provide proper instructions or may interpret the test improperly. For example, an officer may count a person's slow walk as a clue for stopping while walking. Slow walking, however, is specifically identified by the NHTSA as not stopping, but it can be hard to determine what is slow and what is stopping. It all depends on the point of view or interpretation of the officer.

The One-Leg-Stand Test 

The one-leg-stand (OLS) test is a standardized field sobriety test (SFST) used by the police to determine if a driver is operating a vehicle while under the influence of drugs or alcohol. The OLS must be administered in accordance with specific rules. Police are trained on how to administer the OLS during OUI investigations, but that does not mean that they do properly administer this field sobriety test in every investigation.

The one-leg-stand test requires the individual to stand on one foot with the other foot elevated approximately six inches from the ground. While maintaining balance, the individual must count aloud until the law enforcement officer orders the individual to stop and put their foot down. The individual must also keep his or her eyes on the elevated foot while counting and maintaining balance. As such, the OLS is another divided attention test.

There are four clues an officer looks for while you stand with one leg up, counting out loud:

  1. Swaying back and forth or side to side while balancing;
  2. Raising arms for balance;
  3. Hopping but keeping your balance; and
  4. Putting a foot down. 

Supposedly, if you "fail" two clues, this indicates your blood alcohol content (BAC) level is greater than 0.08 percent. The police can use this in conjunction with another SFST as probable cause to arrest you.

However, the one-leg-stand test is fraught with problems, making it unreliable and vulnerable to challenges in court, including environmental factors (e.g., noise, road conditions, weather), medical conditions (e.g., hearing, joint or muscle problems). In addition, even being nervous could cause you to not perform as expected.

And of course, police officers make mistakes. The OLS, like the other SFSTs, should be administered properly. The instructions are strict and very technical. An error on the police officer's part can lead to criminal consequences for you. Errors can include anything from confusing instructions to a failure to keep track of the time.

As your OUI defense attorney in Portland, we will question you about exactly how the officer administer the test, and we will review any available video recordings of the OUI investigation to determine if the officer may have made a mistake.

Contact Our OUI Defense Lawyers in Maine Today

Field sobriety tests are a way police officers gather probable cause to arrest you for OUI charges. These tests, however, are rarely conducted in accordance with regulations and are faulty given their subjective nature.

At the Law Offices of Dylan Boyd, in Portland, our OUI defense lawyers know how to prepare and challenge field sobriety tests. To learn more about how we can help your OUI case, contact us by filling out the online form or calling us at (207) 536-7147 to schedule a consultation.

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