Rarely Accurate and Limited Value as Evidence.
Skilled Cross Examination of Police Officer a Must.

The general scientific community has not accepted the field sobriety tests in use today as an accurate method to measure the quantity of alcohol in one's blood or to prove the alleged state of intoxication.  Yet prosecutors regularly introduce field sobriety test results into evidence in DUI trials and police officers routinely testify about field sobriety test administration.

If you are a defendant in a DUI case, you should never simply accept without objection or cross-examination field sobriety test evidence.  With Guy Sharpe in your corner, you can rest assured that any field sobriety evidence in your case will be thoroughly evaluated and vigorously contested if the arresting officer administered these tests properly.

While field sobriety test evidence can be relevant, Guy Sharpe often finds that he can challenge the arresting officer's reports and therefore move to exclude from trial evidence that you failed a field sobriety evaluation.  Guy's extensive knowledge about field sobriety evidence comes from both academic study and real world trial experience.

One of the few attorney attendees of a 20 hour course sponsored by the National Highway Traffic Safety Administration for DUI detection and standardized field sobriety testing, Guy understands in great detail the procedures recommended by the National Highway Traffic Safety Administration for the administration of field sobriety tests. He learned how to determine whether or not the tests were properly administered by the police, and whether or not the police officer was following recommended guidelines when administering and interpreting the results of the tests given to those arrested for DUI. He is prepared to ask the arresting officer tough questions about the field sobriety tests administered to his clients.

If your DUI arrest involved a field sobriety test, please call Guy Sharpe to discuss what happened to you and whether a compelling argument exists to exclude evidence of a failed test.

Arrested after a Georgia DUI Test


Horizontal Gaze Nystagmus Test

The horizontal gaze nystagmus test measures the eyes ability to follow a moving object in a horizontal and sometimes vertical plane. If one has consumed too much alcohol, the eye muscles twitch involuntarily when moved to the extremes of left and right. They may twitch when following a pen or finger indicating a lack of smooth pursuit. Provided the horizontal gaze nystagmus test is administered properly, the test has a reliability factor of 77% that the person being tested will score more than .08 on a blood alcohol test.


Walk And Turn Test

The walk and turn test is a divided attention test. It is intended to test your ability to follow instructions while standing heel to toe during the instruction stage. It also tests your physical ability to walk a line, or an imaginary line, for 9 steps, turn around in small steps to your left, and return by taking 9 steps, heel to toe. Of course, if you raise your hands, wobble, show any unsteadiness, miss heel to toe, and walk the incorrect number of steps, these factors will be counted against you. The reliability factor for the walk and turn test is 68% that the person being tested will score more than .08 on a blood alcohol test.


One Leg Stand Test

One leg stand testThe one leg stand test is designed to test a person's ability to balance on one foot, while raising the other 6 inches off of the ground, and count 1 to 30. If you waive your arms, hop, put your raised foot down, or count incorrectly, you are counted off for those factors. The reliability index for the one leg stand test is 65% that the person taking the test will score more than .08 on a blood alcohol test.

These are the three tests recommended by the National Highway Traffic Safety Administration. In addition to the above, your local police may require you to count backward, say your A B C's, touch your finger to your nose, and other un-named tests. Other tests are frequently given by the police in an effort to try to measure a person's responses and make a determination as to whether or not the person being investigated should be arrested for DUI.


Portable Alcosensor Test

In addition to the physical dexterity exercises mentioned above, the police frequently use a portable "alcosensor" to measure the quantity of alcohol in a person's blood prior to arrest. The portable alcosensor is not accepted as "evidence" to prove that the person has a certain measurement of alcohol present in their body, due to their unreliability. Therefore, the digital results of the "alcosensor" are only useful to the police to help them determine whether or not to arrest the person being investigated. You have every right to refuse to blow into the portable "alcosensor". You also have the right to refuse to do any of the field sobriety exercises mentioned above.



I recently read an interesting article about inaccuracy of breath tests.  Research studies have shown that how you breathe (first part of your blowing into the machine vs. last exhale, effect of hyperventilating, etc.) will cause wildly different breath test results.  You can read more about this issue at my Marietta DUI blog post.

If you refuse to blow into the portable alcosensor, or perform any physical dexterity exercises, you may be told that you are going to be arrested if you don't do them. If you elect to perform these field sobriety exercises, you do so at your risk. Under stressful conditions, few people can perform all of the tests perfectly. Remember, all you are doing is giving the police further evidence of your possible intoxication. This evidence will be used to help prosecute you should you be arrested after performing these field sobriety exercises.


It was extremely gratifying to have a person of your integrity and attorney of your caliber as my defense counsel. I know that without my having the benefit of your substantial experience and expertise the prosecution would have prevailed... Without reservation, I highly recommend your services.
- Dr. A. J.
Former Client
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Guy Sharpe, Personal Injury & Criminal Defense Lawyer


Phone: (770) 590-9090


Email: guy@guysharpe.com



Online: Request Consultation or DUI Case Evaluation


Mailing Address: 1635 Old Hwy 41 NW, Suite 112344, Kennesaw, Ga., 30152