If you are pulled over for drinking and driving in northern Virginia, there are only three Standardized Field Sobriety Tests that police can use to determine if there is probable cause for arrest.

Unfortunately, police officers use many other tests to try and prove that someone is allegedly driving under the influence, such as the alphabet test and counting backwards. If law enforcement officers use other field tests besides the standardized ones, the results of the other tests are not admissible in court.

The standardized tests are a battery of three tests that were developed by the National Highway Traffic Safety Administration (NHTSA). These tests are referred to as the Standardized Field Sobriety Tests (SFST) and came about after conducting research that would help law enforcement better detect DWI and DUI suspects.

The three tests are:
  • Horizontal Gaze Nystagmus (HGN) - with this test, a jerking movement of the eyeball occurs when a person gazes to the side. If a driver is driving under the influence of alcohol, the jerking motion is exaggerated and happens at smaller angles. Also, someone who is impaired will find it more difficult to follow a moving object with their eyes.
  • One- Leg Stand (OLS) - with this test, the driver has to stand with one foot raised about six inches off the ground and count aloud for thirty seconds. Law enforcement looks to see if the individual sways, uses their arms to balance, hops to sustain balance, or puts their foot down. 
  • Walk-and-Turn (WAT) - with this test, the driver has to take nine steps in a straight line (heel-to-toe). Once those steps are completed, the individual has to turn on one foot and return by walking that straight line again. Officers are looking for the individual to listen and follow instructions, use of arms to balance, losing balance while turning, and touching heel-to-toe.
Although these tests can be used in court, many people have trouble with balance even when sober. These tests are primarily psychological tests that help an officer to determine if a driver might be driving under the influence (DUI) or driving while intoxicated (DWI). However, these tests may have not been administered correctly or the test results could have been interpreted incorrectly. An experienced Virginia DUI defense attorney may be able to determine the effectiveness of the SFST.

If you have been charged with a DUI in Virginia, there are possible defenses that may be used in your case.
Contact a knowledgeable Manassas, Virginia DUI attorney to find out your options. Call T. Kevin Wilson, an experienced Virginia DUI defense lawyer at the Wilson Law Firm, toll free at (800) DUI - LWYR or (703) 361-6100 today. In addition, make sure you download a copy of our FREE book DUI/DWI Virginia Arrest Survival Guide - The Guilt Myth, which can be of help to you during this time.