Queens County Bar Association
Martindale Hubbell - Distinguished 2023

The Purpose and Types of Field Sobriety Tests

The purpose of the field sobriety test is to help determine if there is probable cause to believe a driver is intoxicated. It is usually done when a vehicle is stopped by police — usually for erratic driving or for a traffic infraction — when the officer suspects the driver is intoxicated. The signs of intoxication include, but are not limited to, the smell of alcohol on his breath or clothes, red or weepy eyes, slurred speech, lack of balance, and his general demeanor. After the driver is removed from his vehicle, he will be asked to perform at least the three standardized field sobriety tests. These tests are 1) the horizontal gaze nystagmus, 2) the walk and turn test, and 3) the one-leg stand test.

The horizontal gaze nystagmus test requires the officer to hold an object about a foot in front of the subject’s nose, moving it smoothly side to side. NYstagmus is an involuntary jerking of the eye(s) as it moves to the side. The officer is looking for three things that indicate intoxication: 1) lack of smooth pursuit; 2) distinct nystagmus at maximum deviation; 3) onset of nystagmus prior to reaching 45 degrees. He will check each one for each eye and will do the tests twice. Failure to properly complete four of the six items allegedly indicates intoxication.

It’s important to know that other conditions or drugs can cause these effects. Moreover, a positive result is certainly not conclusive of intoxication.

The walk and turn test is designed to test the subject’s ability to effectively divide attention. Besides the obvious requirement of maintaining balance while walking heel to toe, the subject is given multiple instructions, e.g., how many steps, when to turn, counting out loud, etc. While I consider myself reasonably intelligent and fairly athletic, I cannot perform this test perfectly even when stone sober.

The one-leg stand test requires the subject to stand on one leg with the other 6 to 12 inches off the ground pointed straight out, arms to the side, counting out at least 30 seconds. Don’t sway or move your hands for balance. If you’re a young, stone-sober athlete, you shouldn’t have much trouble with this test. Otherwise, good luck!

There are several other equally ambiguous tests that are used by different police forces, but these are the big three. So, if an officer pulls you over, are you required to submit to these tests? The answer is generally no, but your refusal is unlikely to keep you from being arrested. Moreover, evidence of your refusal to take the tests can be used as evidence against you. On the other hand, your refusal to take these field tests will not result in a motor vehicle bureau revocation of your license, as that law states that you are deemed to consent only to chemical tests.

None of these tests have any real scientific basis. The results will vary greatly depending on the physical and even mental condition of the subject being tested under very stressful conditions. The results are also determined by the very subjective (and biased?) opinion of the officer looking to arrest you. My own opinion is that a driver is better off taking these tests and relying on his attorney to show how meaningless they are, rather than giving the prosecutor the opportunity to stress to the jury that you refused to take the tests.

Alco-Sensor (Breath Screening Test)

The administration of an Alco-Sensor or breath test is also done at the place the motorist is stopped and may also be considered a field test. It is important to note that the Alco-Sensor test does not accurately measure the level of alcohol consumed. It does nothing more than reliably show that there is alcohol on the subject’s breath. The results of an Alco-Sensor test are generally not admissible at trial to prove intoxication.

Under ordinary circumstances, a motorist is not required to submit to an Alco-Sensor test on pain of having the MVB revoke his license for refusing to submit to a chemical blood-alcohol test. Again, the Alco-Sensor is NOT a chemical test. The Vehicle and Traffic Law does require submission to the test if 1) the motorist was involved in a traffic accident, or 2) committed a VTL violation. Even here, there are no loss-of-license consequences for failing to take this test.

In real practice, the results of the field tests, including the Alco-Sensor, play little or no part in the actual trial of a DWI case. Their real importance is in determining whether these tests, including even more subjective observations by the officer, are sufficient to provide probable cause for the motorist’s arrest. If your attorney can show that the results are clearly ambiguous and that the officer lacked probable cause to arrest, all of the more meaningful and reliable evidence obtained after the arrest will be inadmissible at trial. That includes the very reliable chemical alcohol level test, the IDTU observations and tests and the video recording of these tests, without which it is virtually impossible to convict the motorist.

For more information, contact The Law Office of Martin D. Kane by calling (718) 793-5700.

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