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Breaking Down Field Sobriety Tests

When you get pulled over on suspicion of driving under the influence (DUI) in New Jersey, you may be asked to submit to two types of tests: (i) a chemical test (typically a breath test), and (ii) a series of field sobriety tests (FSTs). While submitting to the breath test is mandatory under New Jersey’s implied consent law, you do not have to consent to the FSTs. But, let’s say you didn’t know your rights, you felt confident in your ability to pass, or you felt pressured into taking the FSTs. If you “failed” a field sobriety test, how will your test results impact your DUI trial?

Understanding the Field Sobriety Tests Used in New Jersey

In New Jersey, the police use the three standardized field sobriety tests that have been validated by the National Highway Traffic Safety Administration (NHTSA): (i) the horizontal gaze nystagmus test, (ii) the walk-and-turn test and (iii) the one-leg stand test. When administering each of these FSTs, the arresting officer must follow the instructions provided by the NHTSA, and must assess the DUI suspect’s performance in light of specific enumerated factors. These factors include:

1. Horizontal Gaze Nystagmus Test

  • Lack of smooth tracking in either the left or right eye
  • Onset of nystagmus in either eye prior to 45 degrees of movement
  • Sustained nystagmus (involuntary eye movement) in either eye at full deviation
  • Nystagmus in either eye when looking upward (vertical gaze nystagmus)

2. Walk-and-Turn Test

  • Failure to maintain balance during the test instructions
  • Starting too soon
  • Stopping before completion
  • Failing to maintain heel-to-toe contact
  • Stepping off of the line
  • Using the arms for balance
  • Making an improper turn or taking an incorrect number of steps

3. One-Leg Stand Test

  • Swaying while balancing
  • Using the arms for balance
  • Hopping
  • Putting down the raised foot

A New Jersey DUI Lawyer Can Help You Defend Against an FST Failure

If you were arrested after consenting to the field sobriety tests, the prosecutor’s office will probably try to use your performance on the FSTs as evidence at trial. But, while “failing” a field sobriety test can be evidence of alcohol intoxication, it can also be representative of various other facts and circumstances. For example, DUI defendants in New Jersey will often be able to challenge the use of their FST results at trial by asserting defenses such as:

Having acquired nystagmus 

Acquired nystagmus is a medical condition that has nothing to do with your level of alcohol impairment. It is caused by an underlying medical condition, and it can cause involuntary eye movements even if you are completely sober. Some of the most common causes of acquired nystagmus include inner ear conditions, multiple sclerosis, head injuries, and strokes. It can be a congenital condition as well.

Having another medical condition that makes it difficult for you to track movement with your eyes or maintain your balance 

Along with acquired nystagmus, several other medical conditions can make it difficult (or impossible) for you to pass the field sobriety tests. For example, inner ear conditions can cause a lack of balance (in addition to causing acquired nystagmus), and physical injuries such as sprained ankles or lower back pain can negatively impact your ability to maintain your balance as well.

Inadequate communication of the test instructions

Prior to administering the field sobriety tests, an arresting officer must clearly communicate the test instructions in a language you can understand. If your arresting officer did not adequately explain what you needed to do, or if you could not understand what your arresting officer was saying (i.e., because English is your second language), this isn’t your fault, and you don’t deserve to be convicted because of it.

Improper FST administration 

The field sobriety tests are supposed to be “standardized.” This means that the police must administer them the exact same way during every single traffic stop. If your arresting officer did not administer the FSTs properly, then your test results may be unreliable. This is true even if you understood the instructions you were provided.

Improper interpretation of test performance 

In addition to properly administering the field sobriety tests, your arresting officer must also properly interpret your performance. Did you really lose your balance? If so, was there a possible explanation besides alcohol impairment? If your performance on the FSTs is not clearly indicative of drunkenness, then it should not be used against you.

Use of non-standardized tests or procedures 

In some cases, police officers who are not adequately familiar with the standardized field sobriety tests may use non-standardized tests or procedures. Since these non-standardized tests and procedures have not been proven as effective means to assess alcohol impairment, they are not valid evidence in a DUI case.

Being asked to perform the FSTs on sloped or uneven terrain 

Trying to stand on one leg or walk in a straight line on sloped or uneven terrain can be difficult even if you are sober. Gravel, puddles, debris and various other issues can make passing the FSTs difficult as well. If there is any possible explanation for your FST failure, this could be enough to prevent the judge from finding you guilty beyond a reasonable doubt.

Poor lighting or weather conditions 

Similar to poor road and shoulder conditions, poor lighting and weather conditions can also negatively impact your performance on the field sobriety tests. Passing cars’ headlights can divert your gaze, and rain or snow can impair your ability to stand on one leg or walk heel-to-toe.

Wearing boots or shoes that make it difficult to balance on one foot or walk heel-to-toe 

High heels, slippery soles and other issues with your boots or shoes can also cause you to fail the FSTs. While your arresting officer might not take your complaints seriously on the side of the road, a judge will be forced to consider whether your footwear is to blame for your FST “failure.”  

Can you successfully challenge the prosecution’s evidence against you? Given the severe consequences of a DUI conviction in New Jersey, you need to find out. To discuss your case with an experienced New Jersey DUI lawyer in confidence, schedule a confidential initial consultation today.

Schedule a Confidential Initial Consultation to Discuss Your Options at Helmer, Conley & Kasselman, P.A.

If you have been arrested for DUI, our New Jersey DUI lawyer can fight to prevent your field sobriety test results from being used against you. To request an appointment at one of our 14 convenient office locations, please call 1-877-435-6371 or get in touch online today.

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