Types of field sobriety tests and their admissibility in court

When people in Pennsylvania are pulled over by officers who suspect that they might be under the influence of alcohol, they may be asked to perform several tests at the roadside. There are types of field sobriety tests and their admissibility in court or known as SFST’s. There are three tests that officers might conduct to try to develop probable cause for a DUI arrest. These tests include the horizontal gaze nystagmus, the one-leg stand, and the walk-and-turn. Unlike chemical tests after an arrest, people are not legally required to submit to SFST’s. However, if they do, they may wonder whether the tests are admissible in court. Here is what the legal team at DiCindio Law thinks that you should know about SFST’s and their admissibility.

What are the standardized field sobriety tests?

The standardized field sobriety tests are a battery of tests that were created and standardized by the National Highway Traffic Safety Administration in the 1970’s and 1980’s. When these tests are properly administered, the NHTSA claims that they are effective in helping to determine whether a motorist is under the influence of alcohol. However, the tests are subjective and are frequently not administered according to the standards. They also do not work for all people because of medical conditions and other issues that might impact motor control and eye movements. The three standardized tests include the horizontal gaze nystagmus, the walk-and-turn, and the one-leg stand. Officers might also ask people to submit to other field sobriety tests that are not standardized.

Horizontal gaze nystagmus test

The HGN test looks for an involuntary jerking movement of the eyes when they move to look to the side. Normally, nystagmus happens when people’s eyes are rotated at high side angles. In people who are under the influence of alcohol, the jerking motions are exaggerated and may be seen at smaller angles. People who are impaired by alcohol also have trouble tracking a moving object with their eyes. In this test, the police officer uses a pen and asks the person to track it with his or her eyes as the officer slowly moves it to the side. The officer observes the person’s eyes to watch for three things. The officer will look to see if the person’s eyes are unable to smoothly track the object. He or she will also look for distinct and sustained jerking motions when the eyes reach the maximum deviation and if the jerking is observed before the eyes reach a 45-degree angle from the center.

Walk-and-turn test

The walk-and-turn test is the second of the three SFST’s. In this test, the officer asks the person to take nine heel-to-toe steps on a straight line. Once the person takes the steps, he or she is asked to turn around on one foot and return in the same way back to the starting point. 

The officer will watch to see if the person exhibits any of the eight following signs that might indicate that he or she is impaired:

  • Inability to maintain balance while being told the instructions
  • Starting to walk before the officer has finished giving the instructions
  • Stopping during the walk to regain balance
  • Not touching heel-to-toe
  • Extending arms out for balance
  • Stepping off of the line
  • Taking the wrong number of steps
  • Turning improperly

One-leg stand test

The one-leg stand test involves the officer asking the person to stand while having one foot extended in front of him or her around six inches off of the ground. While maintaining the foot off of the ground, the person is told to count by one thousand and one, one thousand and two, etc. until he or she is told to return his or her foot to the ground. The officer will time the person for 30 seconds. The signs that the officer will look for include swaying, extending the arms for balance, hopping, or putting the foot down early.

Problems with the tests

Multiple problems can make someone unable to complete the tests successfully. For example, some medical conditions or eye diseases cause nystagmus. Many people suffer from health conditions that affect their balance and their ability to complete the walk-and-turn and the one-leg stand. Generally, police officers should ask people whether they have any medical conditions or reasons that make them unable to complete the tests. If a person tells the officer that he or she does, the officer should write the condition down in the report.

Are the results of SFST’s admissible?

The NHTSA created a standard for the procedures for administering SFST’s in 1981. However, it is a federal standard that states are not required to follow. Out of the three SFSTs, the one-legged stand and the walk-and-turn are generally considered to be admissible at trial. The third test, the HGN test, is not admissible at trial in Pennsylvania. However, it is admissible for use in a probable cause hearing. For the one-legged stand and the walk-and-turn tests, a lawyer can review the administration of the tests and challenge the officer about any deviations from the standard established by the NHTSA. Since the HGN is based on the person’s eye movements that cannot be seen, it is more difficult to challenge how it was administered.

Your attorney may request copies of the video of your SFST’s during the discovery process. He or she can then review how the tests were administered and your performance on the tests. If the officer administered the tests incorrectly, your lawyer may file a motion to challenge their admissibility at trial in your DUI case. If the motion is granted, the prosecutor will not be able to present them as evidence against you at trial.

Contact DiCindio Law

Getting pulled over for a suspected DUI can be scary. If you were arrested after an officer performed standardized field sobriety tests, it is important to review the video carefully. Michael DiCindio at DiCindio Law understands how these tests should be administered and can challenge any errors that he observes. Contact us today to schedule an appointment by calling us at (610) 430-3535.