Standardized Field Sobriety Testing

There are many misconceptions revolving around the tests given when a driver is pulled over under suspicion of driving while under the influence of alcohol or drugs. The tests that officers are taught to administer during a DWI stop is called Standardized Field Sobriety Testing. Prosecutors use the recorded results of these standard tests in prosecuting DWI cases. There are three tests performed during standardized field sobriety testing.

1. Horizontal Gaze Nystagmus Test:

In this test the officer has the suspected offender follow the motion of a small object such as a pen with their eyes only, keeping the head still. An involuntary jerking of the eye when you gaze toward the side becomes more easily noticeable when one is impaired. Increased blood alcohol concentrations causes the eye to jerk sooner as it moves to the side. Main indicators of intoxication include the eyes inability to smoothly follow a moving object, eye jerking prior to a 45-degree angle from the center of the eye, and sustained distinct jerking when the eye is held at maximum deviation.

2. Walk-and-Turn Test:

This test is a divided attention test with two main stages. The first stage is the instruction stage. During the instruction stage the suspected offender must stand with their arms at their sides and their feet in a heel to toe position while listening to instructions for the second stage of the test. The second stage is the walking stage. In this stage the person must walk a line taking nine steps heel to toe, turn keeping their front foot on the line, and take nine steps heel to toe back to the initial spot. They must count the steps out load as well as keep their eyes on their feet during the second stage of this test. Typical indicators of intoxication during this test include poor balance during instructions, beginning phase two prior to the completion of instructions, stopping or stepping off of the line during walking, wrong step count, poor balance during walking, and not touching the heel to the toe.

3. One-Leg Stand Test:

This is another divided attention test with two stages. The first stage is the instruction stage. This is similar to the instruction stage for the walk-and-turn test. The second stage is the balancing and counting stage. In this stage the suspected offender raises one foot off of the ground approximately six inches, keeping the raised foot parallel with the ground. They must count in a specified manner while looking at the raised foot until told to stop. The officer should instruct them to stop after thirty second have passed. Indicators of impairment include poor balance and swaying, use of arms to help with balance, and putting the raised foot down or hopping.

It is important to note that while some jurisdictions may allow an officer to implement other field sobriety tests or a preliminary breath test (breathalyzer) that these tests are not considered standard field sobriety tests. Although these may not be standardized field sobriety tests, this does not mean that they may not be used as evidence in the prosecution of a DWI case. All field sobriety tests are administered in an attempt to gather probable cause for an arrest which triggers the officer’s authority to request that suspect submit to a chemical breath test.

Standardized field sobriety testing is not 100% accurate

Standardized field sobriety tests have research to support their validity, however this research does not show that these tests give 100% accuracy in detecting intoxication. Not only must these tests be administered properly, which often requires specific instructions and order of instructions to be completed properly, but the results must be properly interpreted which can be an equally difficult task. There are also many factors that may lead to “false positives” in terms of detecting impairment through field sobriety tests such as eye disease, injury, or other pre-existing conditions.

If you have been charged with DWI It is important to hire an experienced DWI attorney who understands the field sobriety tests used by officers and how these tests and their results may affect your case. Team Green Lawyers is a group of experienced attorneys who understand the intricacies of DWI cases and the evidence that must be gathered for their prosecution. At Team Green Lawyers we work with you to build the best possible defense and provide you with the best outcome.

http://oag.dc.gov/sites/default/files/dc/sites/oag/publication/attachments/SFST_PM_Full_Manual_Part1.pdf

http://oag.dc.gov/sites/default/files/dc/sites/oag/publication/attachments/SFST_PM_Full_Manual_Part2.pdf

http://duijusticelink.aaa.com/issues/detection/standard-field-sobriety-test-sfst-and-admissibility/