It is usually nerve-wracking to see the flashing of red & blue lights that characterize traffic stops. Traffic police officers may arrest you at these stops, and you may end up facing DUI charges. However, as with any other arrest, law enforcement officers need to have probable cause for a DUI arrest. As part of the judicial process, police officers at traffic stops are required to conduct mandatory field sobriety tests (FSTs) on suspected impaired drivers. Police officers also use the tests to determine whether intoxication is by alcohol or drugs. Considering the importance of FSTs in Driving Under the Influence cases, it is critical to know what they are, their degree of reliability, and how they will affect you if and when you are pulled over for suspected DUI. Still, we invite you to seek our services at the San Jose DUI Attorney Law Firm if you have been arrested at these stops and want to challenge the evidence presented against you.

An Overview of Field Sobriety Tests (FSTs)

FSTs are a group of physical tests that police officers use to enforce Driving Under the Influence laws. The collection of tests is usually the first test that law enforcers administer on suspicion of impaired driving. To determine impaired driving, police officers use these tests to observe drivers’ physical abilities and attention levels.

Since FSTs cannot determine a suspect's blood-alcohol concentration, police officers usually administer a breathalyzer test to validate the arrest for those who fail the tests. Field sobriety tests, also known as roadside sobriety tests, are categorized into standardized and non-standardized tests. While the National Highway Traffic Safety Administration (NHTSA) has endorsed only three standardized FSTs, there are numerous non-standardized FSTs used by law enforcement agents.

Standardized Field Sobriety Tests (SFSTs)

The NHTSA-approved SFSTs include walk-and-turn, one-leg stand, and horizontal gaze nystagmus (HGN). Standardized means their application or administration is uniform across the board. Essentially, the law enforcers must follow specific guidelines when administering the tests.

Horizontal Gaze Nystagmus (HGN)

Nystagmus is a medical term referring to the involuntary jerking of the eyeballs. Eye jerking is a natural occurrence, but it gets more pronounced when a person is drunk. The test involves a law enforcement officer holding a small object or stimulus approximately 13 inches from your face and slowly moving it from one side to another. The officer uses the following signs to conclude that you are impaired:

  • An inability to smoothly and slowly follow a moving object
  • Distinct or exaggerated nystagmus with the eye at maximum deviation
  • Eye-jerking beginning before the eyes gets to a 45-degree angle

If an officer observes more than one of these indicators at once, you will be considered to have failed the test. However, before administering HGN, police officers are supposed to examine for any medical condition that might make the test unreliable, including equal pupil size and resting nystagmus.

Walk and Turn

This test, as its name suggests, involves walking along a straight line and turning on one foot and returning in the opposite direction. However, as a standardized test, the officer administering the test must follow specific guidelines in the instruction and performance stages. During the instruction stage, the law enforcement officer will ask you to stand heel-to-toe as they explain and demonstrate how you should perform the test. The officer is required to confirm whether you have understood his or her instructions before asking you to complete the test.

During the performance stage, you will be required to take nine heel-to-toe forward steps along a straight line, turn on one foot, and take nine steps back to the starting point. The straight line can either be real or imaginary. In the performance stage, the officer will look for several indicators of alcohol or drug impairment, including:

  • Stepping off the line
  • Failing to walk heel-to-toe
  • Stopping while walking
  • Taking an incorrect number of steps
  • Inability to balance and listen to instructions at the same time
  • Improper turning or losing balance while turning

If an officer observes two or more of the above indicators, you are considered to have failed the test. The purpose of the test is to determine your ability to complete a simple task with undivided attention.

One-Leg Stand

Similar to the walk-and-turn, the one-leg stand test is composed of an instruction and a performance stage. During the instruction stage, the law enforcement agent explains and demonstrates how you should perform the exercise. After confirming that you have understood the instructions, the officer directs you to proceed to the performance stage.

The test requires the suspect to stand with one foot approximately six inches above the ground. With their hands on the side, he or she is then required to count for thirty seconds or until instructed to stop. Indicators or clues of possible alcohol impairment include:

  • Swaying while maintaining balance
  • Hopping
  • Balancing using arms
  • Putting your foot down before completing the test

A suspect is considered to have failed the test if the law enforcement agent observes two or more of these indicators. Generally, the test checks whether a suspect can divide his or her attention between verbal instructions and the simple physical task of standing on one foot for 30 seconds.

Non-Standardized Field Sobriety Tests (NSFSTs)

To complement SFSTs, law enforcers may use non-standardized FSTs, including the hand pat test, the finger count test, and the finger-to-nose test.

The Hand-pat Test

It involves a suspect patting one side of the hand in alternating movements while counting. The test is meant to determine the degree of undivided attention that the DUI suspect can give to a task.

The Finger Count Test

It involves the suspect putting one of their hands in front with its palm facing upward and then using the top of its thumb to touch the tips of the other fingers. The suspect has to accompany the finger-thumb connections with counting out loud.

The Finger-to-nose Test

It involves the DUI suspect using the tip of their index finger to touch the tip of their nose with their eyes closed while slightly tipping their head backward. The suspect is then required to repeat the movement a couple of times with each hand. The test has been in use in California for a long time.

Other tests that fall under this category include Rhomberg balance, the vertical gaze nystagmus (VGN), the ABC test, and counting forward and backward test. The officer may also ask the suspect to stand with feet together and tip their head backward.

Most NSFSTs complement standardized tests when determining a suspect's ability to follow instructions. However, most of the NSFSTs are not scientifically validated hence are not admissible as court evidence in many states. Unlike SFSTs, the non-standardized tests tend to vary from one law enforcement officer to the next. The correlation between these tests and alcohol or drug impairment is also highly questionable. Despite these legitimacy issues, some non-standardized tests are popular among police officers, including in California.

Standardized Field Sobriety Tests as Court Evidence

Since NHTSA scientifically validated SFTSs, they are accepted by courts in most states as evidence. Each of the three SFTSs has been designed to measure specific physical responses that NHTSA researchers believe are compromised by a blood alcohol content (BAC) level of .10% or higher.

Since NHTSA developed them in the 1970s, police officers have administered the three SFSTs as a whole. Individually, the three SFSTs have varying degrees of accuracy in determining drunk-driving. However, according to a NHTSA study, as a whole or combined, they have a 91 percent success rate of accurately determining impaired driving. It is this predicted high accuracy rate that has made most states to accept SFSTs as court evidence.

Despite their endorsement by the NHTSA and their acceptance as court evidence, offenders, experts, and legal professionals continue to question their accuracy and reliability in determining impaired driving. There have been suggestions in some NHTSA sanctioned studies of the likelihood of law enforcement agents providing false assessments of impairment. Some stakeholders have often accused officers of giving wrong SFSTs scores and ignoring other underlying factors that may lead to a suspect failing the test. From a failure to follow the set guidelines to other malicious reasons, experts have identified several pertinent issues that raise questions on the reliability of SFSTs as court evidence in DUI cases.

The Reliability of Field Sobriety Tests

Despite their frequent and massive acceptance across states, offenders, attorneys, and other stakeholders, hotly contest their reliability. Stakeholders agree that certain conditions can significantly affect the outcome of field sobriety tests. It is, therefore, imperative for an officer to administer the tests under ideal conditions, including under the right surface, lighting, and sound conditions.

  • Surface – The surface conditions should not be wet, slippery, or uneven. Surfaces under these conditions increase the possibility of the suspect failing both the walk-and-turn and the one-leg stand tests. If the surface at the point of the traffic stop is not ideal, the law enforcement officer is required to find a suitable surface for test administration.
  • Lighting – Similar to bad surfaces, administering the field sobriety tests in a poorly lit area increases the probability of failure. The suspect may be unable to perform the tests as instructed not because they are impaired but because of poor lighting. In this case, the police officer is required to find a well-lit area or provide additional lighting, either using a flashlight or other temporary means.
  • Sound – FSTs should not be administered in noisy surroundings as the loud sounds can hinder a suspect from hearing instructions. The police officer may wrongly judge a suspect as impaired even though their inability to listen and follow directions is as a result of the surrounding noise.

Meeting the above conditions is considered an ideal scenario for performing a field sobriety test, and any law enforcement agent who proceeds with a test without these minimum conditions is in breach of the established guidelines. However, even under these ideal conditions, the reliability of SFSTs is still weak and can be challenged in a court of law. Other additional factors that support such challenges include:

  • Failure by the police officer to give clear instructions
  • The existence of physical or mental conditions unrelated to intoxication at the time of the test.
  • Any action by the police officer, including movements, that increases the suspect's chances of failing the test
  • Attires such as high heels or tight pants at the time of the field sobriety test may also affect a suspect's ability to complete some tests such as the walk-and-turn test successfully

Even in ideal conditions, the above factors create a strong foundation for your attorney to challenge the field sobriety tests, hence strengthening your defense.

Challenging Standardized Field Sobriety Tests

While the burden of proof is on the prosecution, you should be able to defend the position that your failure in the FSTs is not indicative of impairment. With the help of a skilled and experienced attorney, you can successfully challenge the accuracy of the field sobriety tests and their administration process.

  1. Challenging the SFSTs Administration Process

Although NHTSA trains police officers on how to administer field sobriety tests, most of them are prone to improper administration. Most of the administration problems are a result of the officers being in a hurry, careless or lazy hence not following the established procedures. For example, a police officer may hurriedly conduct an HGN test under 30 seconds instead of the required minimum of 80 seconds. A suspect may also fail a walk-and-turn test by correctly following an officer's hurried and inaccurate demonstration.

As human beings, police officers are bound to make some mistakes while administering SFSTs. However, many people facing DUI charges are not aware of the opportunity the poor administration mistakes offers them. An administration error on the part of the law enforcement officer provides a solid foundation on which to challenge the SFSTs and the DUI case in general.

According to the NHTSA guidelines, any deviations from what is considered proper administration ultimately compromises the validity of the test results. By adequately citing these gaps or changed elements, an experienced attorney can help you to successfully challenge the use of SFSTs as evidence in your DUI case. In most cases, a successful challenge will lead to the court, excluding the SFSTs evidence from the DUI trial. However, this has to be identified and challenged in due time - the more reason you require a skilled and experienced attorney.

  1. Challenging the Accuracy of the SFSTs

Although they are usually administered together, individually, the three standardized field sobriety tests have a varying and relatively lower degree of accuracy. Despite their combined 91% accuracy rate, according to the NHTSA, the walk-and-turn test is only 66% accurate, the horizon gaze nystagmus is 77% accurate, and the one-leg stand test is only 65% accurate.

When challenging their reliability and admissibility as court evidence, most legal professionals challenge the three SFSTs as individual tests and not as a combined DUI test.

In addition to being only 77% accurate in determining whether or not an individual is impaired, the possibility of a suspect having underlying medical and eye conditions influencing the HGN test is usually a point of contest in court. Even though there is a provision for evaluating underlying medical conditions before an HGN test, attorneys and other experts argue that only a doctor and not a police officer can correctly perform the evaluation.

Even when administered in an ideal scenario, and police officers follow all the guidelines, the predicted 66% accuracy rate of the walk-and-turn test raises questions about its reliability as court evidence. According to legal professionals, specific individuals may find it hard to perform the test regardless of whether they are intoxicated or not. The group of individuals includes people over 65 years of age, individuals with leg or back problems, people on high heels, and overweight individuals. In essence, the test disadvantages this group of individuals. Therefore, it is unfair to use it in court to prosecute DUI cases.

The fact that on its own, the one-leg stand test is only 65% accurate, is reason enough to challenge its admissibility as court evidence. Similar to the walk-and-turn test, the test cannot be accurately performed by everyone, even in ideal situations. For these reasons, you are encouraged to challenge the SFSTs in court primarily if your case is as a result of failing one of the three standardized field sobriety tests.

Refusing to Take Field Sobriety Tests

By requesting you to take a field sobriety test, a police officer already assumes you are impaired. The fact that you can fail these tests even when you have not been drinking should make you hesitant to take them. So, assuming you are aware of all the inadequacies of field sobriety tests as discussed and you refuse to take the tests. What would happen to you, and what does the law say?

As already discussed, field sobriety tests are prone to improper administration hence wrong results. Since the primary objective of these tests is to determine the level of impairment, thus a probable cause of arrest, incorrect results can lead to wrongful arrests and false charges. You should immediately contact your attorney if you suspect your DUI charges are a result of incorrect field sobriety test results. However, before it gets to wrongful arrests and false accusations, you have the right to refuse to take a field sobriety test.

Unlike refusing to take a chemical test, refusing to take a standardized or non-standardized field sobriety test is not illegal in California. Since they are the basis for a DUI arrest, a police officer is not even supposed to arrest you for refusing to take the field sobriety tests. However, the officer can arrest you for other reasons, including hostile behavior and the apparent smell of alcohol or other unlawful substance.

While it is wise to be polite and cooperative at traffic stops, always remember that field sobriety tests are not required under California law. Therefore, you have the right of refusal.

Facing DUI Charges

There is still hope even when you have not refused to take the field sobriety tests and are now facing DUI charges. First, you should understand that a DUI is a serious charge. Hence, you should hire an experienced attorney. The most common DUI-related criminal charges include:

  • Driving under the influence, California Vehicle Code Section 23152(a)
  • Driving with a blood alcohol content (BAC) of .08% or higher, Vehicle Code 23152(b)
  • Driving under the influence of drugs ("DUID"), Vehicle Code 23152(f)
  • Underage DUI, California Vehicle Code Section 23140

Second, you should understand the role your field sobriety tests results play in determining the outcome of your case. They are not only the basis for your arrest, but they also allow law enforcers to administer chemical tests legally. Once you have consented to the field sobriety tests, you cannot refuse to be arrested or to take the chemical tests.  According to California laws, refusing to take a chemical test can lead to enhanced penalties and license suspension.

However, if you suspect that the arresting officer did not follow the due process, you should inform your attorney. Many DUI charges are either reduced or dismissed based on proven inaccuracies or improper administration of the field sobriety tests.

Contact a San Jose DUI Attorney Near Me

With field sobriety tests being admissible court evidence in a majority of states, they play a critical role in the prosecution of DUI cases. Since they determine probable cause for arrest, any impropriety in their administration can lead to the court dropping the DUI charges. To ensure such impropriety is identified and brought to the attention of the court, it is critical for you to have an attorney. Our attorneys at the San Jose DUI Attorney Law Firm have experience defending people who are facing DUI charges, even where field sobriety tests are used as court evidence. To learn more about our services, call us at 408-777-6630.