Rochester Minnesota Sobriety Tests Lawyer

FST Attorney Minnesota

As part of their probable cause determination as to whether a driver is impaired, most police officers conduct field sobriety tests, also known as FSTs. In these cases, the motorist is instructed to step out of the vehicle and engage in a number of physical activities which are designed to test the person's coordination and mental acuity for the purpose of determining intoxication. The three main FSTs are:

• The horizontal gaze nystagmus – HGN,
• The walk-and-turn – WAT, and
• The one-leg stand – OLS.

These three tests have been validated by the National Highway Traffic Safety Administration (NHTSA) which has attempted to standardize the multitude of various field sobriety tests employed by law enforcement agencies around the United States.

These three standardized tests were chosen because there were found to be highly reliable in identifying subjects whose alcohol content was .10 or more. Considered independently, the HGN was 77% accurate, the WAT was 68% accurate, and the OLS was 65% accurate. However, when the HGN was used in combination with the WAT, it was 80% accurate. What that means is that even under a perfect scenario there is a 20% possibility of error.

If you have questions about whether these tests were performed consistent with the NHTSA standards, please contact our Rochester Minnesota DUI attorney, to see how we can help.

The Horizontal Gaze Nystagmus - HGN

Nystagmus is the involuntary jerking of the eyes, occurring as the eyes gaze toward the side, or up or down. Nystagmus is a natural phenomenon and while alcohol and certain other drugs do not cause it, they magnify its effects. There are numerous types of nystagmus; however, for DUI cases, law enforcement primarily focuses horizontal gaze nystagmus – HGN. HGN occurs as the eyes move to the side. To observe for HGN, police are instructed to:

• Hold a pen 12–15 inches in front of the suspect's nose,
• Keep the tip of the pen slightly above the suspect's eyes, and
• Move the pen smoothly to the side.

The police then look for the following standardized clues:

• Lack of smooth pursuit;
• Distinct nystagmus at maximum deviation; and
• Onset of nystagmus prior to 45 degrees.

Despite its high rate of success, HGN is subject to a lot of criticism and is not recognized as a proper procedure in some states due to the fact that it is a medical concept that is being interpreted by non-medically trained officers under less-than-ideal roadside conditions. Additionally, many normal individuals have nystagmus that is genetic or is due to a previous illness.

The Walk-and-Turn Test

The walk-and-turn test is a “divided attention” test that requires an individual to focus on mental and physical tasks at the same time.

The test begins when the driver places his/her feet in a heel-to-toe position, placing the right heel against the left toe, while the officer gives detailed instructions. The divided attention part of the test comes into play when the person is asked not to start the test until the officer has finished the instructions. While this test can be easily done while sober, it is more challenging if you are intoxicated.

The officer will ask the driver to take nine heel-to-toe steps down a line, turn around in a specific way, and take nine heel-to-toe steps back up the line. While they are walking, they must keep their arms at their sides, watch their feet at all times, and count the steps out loud.

The police are instructed to look for the following clues when administering this test:

• If they can keep balance while listening to the instructions;
• If they start before the instructions are finished;
• If they stop while walking to steady themselves;
• If they touch heel-to-toe on every step;
• If they step off the line;
• If they use their arms for balance;
• If they perform an improper turn; and
• If they take an incorrect number of steps.

If the driver fails two or more of these clues, there is a 68% chance that they have a blood alcohol content above ".10".

This test must be performed under ideal conditions otherwise its validity may be compromised. The following conditions significantly affect the reliability of this test:

• Uneven surface
• Slippery surface
• Lack of a clearly visible straight line
• Windy conditions
• Drivers over 65
• Drivers wearing high heels
• Drivers who lack depth perception due to injury in one eye
• Drivers who have leg injuries
  

The One-Leg Stand Test

This test, like the walk-and-turn test, is a divided attention test and it requires the driver to stand on one leg and count in accordance with the instructions of the officer.

Initially, the driver must remain with his/her feet together and their arms down at their sides while listening to the instructions provided by the officer. They cannot begin the test until they are told to do so. The instructions given should be the following:

• Raise either leg approximately six inches off the ground with the toes pointed out,
• Keep both legs straight, arms at your side,
• While holding that position, count out loud for 30 seconds in the following manner: “one thousand and one, one thousand and two,” until told to stop,
• Keep your arms at your sides at all times and keep watching the raised foot.

Once the driver indicates understanding as to what is required, the test begins. The police must remain as motionless as possible when giving this test, and often they fail to do so. The idea behind the test is that few people with a blood alcohol content of .10 or more can maintain their balance for 30 seconds or longer.

These are the clues the police are trained to look for in the one-leg stand test:

• Swaying while trying to maintain the one-leg stand position;
• Using their arms by moving them six or more inches from the side of the body in order to keep balance;
• Hopping to maintain balance; and
• Failing to maintain the one-leg stand position during the 30-second count.

According to the NHTSA research, failing two or more of the above clues means there is a 65% chance that the driver is impaired.

Contact Us Today For a Free Consultation

If you have additional questions about about whether the field sobriety tests were properly given to you, please contact the Dilaveri Law Firm today. We always offer free initial consultations to our client. Call 507.206.6020 or complete our free case evaluation form.