Field Sobriety Test & DWI Charges

How Field Sobriety Tests Work

Texas laws allow for police officers who pull you over when they suspect you are driving under the influence to administer tests to determine possible intoxication, which are known as Standardized Field Sobriety Tests that are regulated by the National Highway Traffic and Safety Administration.  These tests require the officer to have a driver perform certain physical and cognitive actions that can help the officer determine whether you are intoxicated or not.  Our office highly recommends that you refuse to take these tests, as they are not mandatory and can only provide more evidence against you.  However, if you have taken them and are facing DWI charges, our DWI attorney from the Law Offices of Chris S. Barnett can help you fight these charges by providing a strong defense on your behalf. The Standardized Field Sobriety Test Battery (SFSTs) used by law enforcement officers include these three tests:

• Horizontal Gaze Nystagmus ( HGN)
• Walk-and-Turn (WAT)
• One-Leg-Stand (OLS)

Horizontal Gaze Nystagmus

Horizontal gaze nystagmus is an involuntary jerking of the eye which occurs naturally as the eyes gaze to the side. Under normal circumstances, nystagmus occurs when the eyes are rotated at high peripheral angles. However, when a person is impaired by alcohol, nystagmus is exaggerated and may occur at lesser angles. An alcohol-impaired person will also often have difficulty smoothly tracking a moving object. In the HGN test, the officer observes the eyes of a suspect as the suspect follows a slowly moving object such as a pen or small flashlight, horizontally with his or her eyes. The examiner looks for three indicators of impairment in each eye: if the eye cannot follow a moving object smoothly, if jerking is distinct when the eye is at maximum deviation, and if the angle of onset of jerking is within 45 degrees of center.

HGN has been used for years to diagnose gross neurological dysfunction. HGN is a medical test used by doctors to aid in the diagnosis of head injuries and other pathological brain dysfunction. The real problem is police officers are not doctors.  The side of the road is not a medical setting. There are 47 types of nystagmus, seperate from HGN.  There are at least 38 different causes of HGN unrelated to alcohol.  Alcohol can cause HGN, but so can many other conditions.  Simply put, HGN is not the "end-all-be-all" that many police officers believe it is.

Walk-and-Turn

The Walk-and-Turn (WAT) test is one of the two divided attention tests in the SFSTs.  It requires a subject to listen to instructions given by police officer as well as a demonstration.  During the instruction phase the subject is required to stand in a heel-to-toe position for a certain period of time. At the conclusion of the instructions, the subject will then walk in a straight line (often an imaginary line) for nine steps, maintaining heel-to-toe, turn and walk back.

The police officer will be looking for any "mistakes" in the following areas:

1. Cannot keep balance while listening to instructions
2. Starts before the instructions are finished
3. Stops while walking
4. Does not touch heel-to-toe
5. Steps off the line
6. Uses arms to balance
7. Improper turn
8. Incorrect number of steps

One-Leg-Stand

The One-Leg-Stand (OLS) test is the second of the divided attention test in the SFSTs.  Again, there will be instructions and demonstration by the police officer.  Basically, the subject is required to stand on one leg with their arms at their side, while watching the raised foot and counting out loud to 30.  The subject's foot should be 6 inches off the ground with the toe pointed away.

The police officer will be looking for any "mistakes" in the following areas:

1. The subject sways while balancing
2. Uses arms for balance
3. Hopping
4. Puts foot down (prior to 30 seconds)

These tests must all be administered in a very precise way, which can be challenged if the officer failed to follow exact protocol in administering them.  Our office will aggressively dispute any findings from these tests when defending you against DWI charges.

DWI Attorney Fighting For Your Rights

The Law Offices of Chris S. Barnett has helped numerous people throughout Texas and particulary Kerrville, Fredericksburg, Boerne and Llano to fight against their DWI charges.  We know how to present an effective and strong defense and can take apart the prosecutors case by carefully reviewing every aspect of their case.  Don't let the system work against you; let us work towards getting your charges dismissed or reduced by using every means at our disposal.  Call our office today so that we can get started on your defense.

Have you been charged with DWI following a field sobriety test?  Contact a Kerrville DWI Lawyer to find out how we can help you fight your charges.