Field Sobriety Tests

In the state of Pennsylvania, if you are stopped for suspicion of driving under the influence of alcohol or a controlled substance (DUI), the police may ask you to submit to a number of field sobriety tests (FSTs).  Police officers will administer the FSTs to detect signs of driver impairment and to establish probable cause to make an arrest for DUI.  Unfortunately, FSTs are not scientifically reliable indicators of driver impairment.

Challenging Field Sobriety Test Evidence

Prosecutors rely heavily on the results of FSTs to prove that an individual is guilty of DUI.  It is extremely difficult for a prosecutor to achieve a conviction before a judge or jury in a DUI trial if the FST results are exposed as unreliable. I have often been successful in challenging the competency and accuracy of FSTs used in DUI prosecutions.

I have over a decade of experience providing skilled and aggressive representation to individuals facing charges for driving under the influence of alcohol or controlled substances in Bucks County, Montgomery County and the surrounding counties.  Contact me at (215) 752-5282 for a free initial consultation or fill out the confidential contact form for an immediate response.  Appointments are available after business hours and on weekends.

NHTSA Standardized Field Sobriety Tests

The results of FSTs are extremely undependable and are based almost entirely on the subjective opinions of the arresting officer.  Roadside FSTs are often difficult to pass, even for people who are completely sober.  The National Highway Traffic Safety Administration (NHTSA) has approved 3 “standardized” FSTs for determining alcohol-related driver impairment.

The Walk and Turn Test

The walk and turn test is considered a “divided attention” task requiring you to focus your attention on the police officer’s instructions while completing a physical task.  This test requires you to take 9 steps on an imaginary line in a heel-to-toe formation.  You are then required to pivot and walk the 9 steps on the same imaginary line in the opposite direction.  The walk and turn test is divided into an instruction stage and performance stage.

Walk and Turn Performance Clues

While conducting the test, the police officer will look for signs of impairment including:

• The driver cannot keep balance during the instruction stage; or
• The driver starts the test too soon; or
• The driver stops while walking; or
• The driver is unable maintain heel-to-toe while walking; or
• The driver steps off the line; or
• The driver uses his or her arms for balance; or
• The driver makes an improper turn while walking; or
• The driver takes the incorrect number of steps

Walk and Turn Test Scoring Standards

The police officer conducting the walk and turn test will record 1 point for each performance clue observed for a total of no more than 8 points.  According to the NHTSA, drivers who exhibit 2 or more of the performance clues during the walk and turn test are presumed to have a blood alcohol content (BAC) of 0.08% or greater.

The Horizontal Gaze Nystagmus Test

The Horizontal Gaze Nystagmus (HGN) test is used to detect the involuntary, rapid and repetitive movement of the eyes.  During the HGN test, you will be required to keep your head still while following a pen, penlight or other stimulus with your eyes as the police officer moves the object from side to side.  The HGN test is divided into an instruction phase and performance phase.

Horizontal Gaze Nystagmus Performance Clues

While conducting the HGN test, the police officer will look for 3 indicators of impairment in each eye including:

• Lack of smooth pursuit (eyes track equally but the movement is “jerky”); or
• Distinct and sustained nystagmus at maximum deviation (the “bouncing” or “jerking” of the eyes when the iris is taken to the far corner of the eye; or
• Onset of nystagmus prior to 45 degrees (jerking of the eye as it follows an object prior to reaching a 45 degree angle)

According to the NHTSA, the entire HGN test should include a minimum of 14 passes and take a minimum of 76 seconds to complete.

Horizontal Gaze Nystagmus Test Scoring Standards

The police officer conducting the HGN test records 1 point for each performance clue indicated in each eye for a total of no more than 6 points.  If 4 or more performance clues are observed between the 2 eyes, it is likely that the driver’s BAC is 0.08% or above.

The One-Leg Stand Test

The one-leg stand test, like the walk and turn test, is considered a divided attention task requiring you to focus on mental and physical tasks at the same time.  During the one-leg stand test, you must hold your foot straight out approximately 6 inches off the ground while counting from 1,001 to 1030 in sequential order within 30 seconds.  The one-leg stand test is divided into an instruction phase and a performance phase.

The One-Leg Stand Performance Clues

While conducting the one-leg stand test, the police officer will look for the following signs of impairment including:

• The driver sways his or her raised leg or entire body either side-to-side or back-and-forth while balancing; or
• The driver moves his or her arms 6 or more inches from their body to maintain balance; or
• The driver hops during the test to maintain balance; or
• The driver puts his or her foot down 1 or more times within 30 seconds; or

One-Leg Stand Test Scoring Standards

The police officer conducting the one-leg stand test will record 1 point for each performance clue indicated for a total of no more than 4 points.  The driver is likely to have a BAC of 0.08% or above if 2 or more performance clues are observed by the police officer during testing.  The one-leg stand test is also scored as a failure if the driver puts his or her foot down 3 or more times during the 30-second counting sequence.

Alternate Field Sobriety Tests

Many FSTs that the police use during a DUI investigation are considered “non-standardized.”  Non-standardized FSTs are considered even less reliable in measuring driver impairment and intoxication when compared to standardized FSTs.  Non-standardized FSTs are often used by the police when a driver has a medical condition or physical disability that would prevent him or her from completing the standardized FSTs.

Unreliability of Non-Standardized Field Sobriety Tests

There are no reputable scientific studies or research that establish the reliability of non-standardized FSTs in measuring driver impairment or intoxication.  Additionally, non-standardized field sobriety tests are not subject to national standards for administration.  As a result, each police officer can choose to conduct the test according to his or her own preferences instead of using a standardized and consistent procedure.  Common non-standardized FSTs used by the police include:

• Counting Backwards Test: Upon instruction from the police officer, you will be directed to stand with your arms at your sides and to count backwards from a specific number.  The police officer may ask you to count in reverse order from a completely random set of numbers such as counting backwards from the number 68 to the number 32.  During the test, the police officer will look for signs of impairment, including the inability to count, starting or stopping the test too early and failing to follow the test instructions.
• Portable Breath Test: A portable breath test or preliminary breath test (PBT) is a device used by law enforcement to detect the presence of alcohol in individuals suspected of driving while impaired.  It is generally used in addition to other FSTs to establish probable cause for arrest for DUI.  A PBT will often produce an inaccurate test result if the driver has residual alcohol in his or her mouth from mouthwash or cough syrup.  A PBT is not calibrated or tested for accuracy and the test result is not admissible as evidence in a DUI trial.
• Finger Count Test: You will be asked by the police officer to touch the tip of your thumb in turn to the tip of each finger on the same hand while simultaneously counting from 1 to 4.  You will then be required to simultaneously reverse direction on your fingers while counting down from 4 to 1.  During the test, the police officer will look for signs of impairment, including the inability to follow the instructions, the inability to touch one’s fingers as instructed, the inability to perform the correct number of sets and the stopping of the test before being instructed to do so.
• Alphabet Test: You will be asked by the police officer to recite part of the alphabet from the beginning, starting at a letter other than the letter A and stopping at a letter other than the letter Z.  During the test, the police officer will look for signs of impairment, including slurred speech, an inability to correctly recite the alphabet, the starting of the test too soon and a failure to follow directions.
• Finger-To-Nose Test: You will be instructed by the police officer to bring the tip of your index finger to the tip of your nose while your eyes are closed and your head is tilted slightly back.  You will be required to attempt to touch the tip of your nose 3 times with each hand.  During the test, the police officer will look for signs of impairment, including an inability to follow the instructions, swaying, tremors, the inability to hold the finger directly on the tip of the nose and poor depth perception.
• Romberg Test: You will be instructed to stand with your feet together while simultaneously leaning your head back with your arms at your sides. You will be asked to hold this position for approximately 30 seconds.  During the test, the police officer will look for signs of impairment, including swaying, eyelid tremors and an inability to accurately estimate 30 seconds.

Challenging the Field Sobriety Test Evidence

The test results for NHTSA standardized FSTs and non-standardized FSTs are unreliable because they are based largely on the subjective opinions and conclusions of the police officer conducting the tests.  I am highly knowledgeable in the proper procedures for conducting both standardized and non-standardized FSTs.  I will thoroughly investigate the facts and circumstances of each FST administered in your case.  Field sobriety test evidence can be successfully challenged in court in many different ways.

Dash-Cam and Body-Cam Evidence of Field Sobriety Tests

If necessary, I will use an independent defense investigator to subpoena any existing dashboard camera (dash-cam) and body camera (body-cam) video and audio recordings from the vehicle stop.  In some cases, dash-cam and body-cam evidence can be presented for the defense at trial to demonstrate that adverse weather conditions, poor lighting or uneven road conditions affected the reliability of the FST results.

Dash-cam and body-cam evidence can also be used by the defense to establish that accused performed better on the FSTs when compared to the conclusions and observations documented by the police officer in the police reports.  Dash-cam and body-cam evidence can often be used at trial to prove that the police officer conducting the FSTs did not have the proper training to conduct the tests or did not administer the tests according to the NHTSA standards.

Medical Conditions Affecting Field Sobriety Test Results

Field sobriety testing should not be conducted on individuals over the age of 65 or on people more than 50 pounds overweight.  Many different medical conditions can affect the reliability of FSTs including:

• Diabetic nerve damage
• Inner ear conditions (e.g., vertigo, Meniere’s disease)
• Foot conditions
• Neurological disorders (e.g., neuropathy, Parkinson’s disease, MS)
• Eye diseases (e.g., cataracts, macular degeneration, glaucoma)
• Low blood pressure (e.g., dehydration, diabetes, heart conditions)
• Vestibular migraine headache
• Medications (e.g., beta blockers, antidepressants, narcotics)

I will extensively review your medical history to determine if any medical conditions may have interfered with your ability to successfully complete the FSTs conducted by the police.

Start with a Strong Defense

If you have been charged with driving under the influence of alcohol or drugs in Bucks County, Montgomery County or the surrounding counties, it is critical that you act quickly to protect your rights and build the strongest possible defense against the charges.  Phone lines are open 24 hours a day at (215) 752-5282.  Call today for a free initial consultation or fill out the confidential contact form for an immediate response.