When a law enforcement officer pulls one over for suspected drunk or intoxicated driving, they will carry out a few tests to confirm their suspicions. The state has legalized a series of mental and physical exercises law enforcement officers use to determine if the driver is sober or not. These exercises are what are known as Field Sobriety Tests. If one fails any of the tests, it is believed that they are impaired from drugs or alcohol. These tests are critical in allowing the police officer to decide whether to arrest a person. If a person fails, and it is determined that they are drunk driving or intoxicated, they can face prosecution for a DUI offense. The penalties for DUI offenses are severe, and anyone facing DUI charges needs to hire a lawyer to fight the allegations. At The DUI Defense Attorney, we are able to help you fight these allegations, which sometimes could be wrongly brought against you.

Field Sobriety Tests in California

The federal government has an agency that issues the protocols to law enforcement officers on carrying out sobriety tests in the field. This agency is known as the National Highway Transportation Safety Administration (NHTSA).

This agency has validated three tests as the most reliable ones amongst all the other tests available. These tests are:

  • WAT – Walking and turning sobriety tests
  • OLS – one-leg standing sobriety test
  • HGN – Horizontal gaze nystagmus test

These are the generally standardized sobriety tests that are administered in the field by police officers. If applied correctly, they are believed to be the most reliable in predicting how a driver is impaired.

The Horizontal Gaze Nystagmus Test (HGN)

This test involves involuntary jerking or movement of one’s eyes when they try to move their eyes from one side to the other. Aside from the movement being involuntary, an individual with whom the test is being administered is not aware of the happening.

Nystagmus tests exist in various kinds, with just a few being affected by alcohol. When one is pulled over for a suspected DUI, they are given the horizontal gaze nystagmus. As a law enforcement officer administers this sobriety test, he would ask the suspect to use their eyes to follow perhaps an object from right to left. Meanwhile, the officer will be looking to establish when the pupil begins to show nystagmus.

If the nystagmus starts earlier than usual or before getting to an angle of 45 degrees, this is believed to be a result of elevated blood alcohol concentrations. The accuracy of this kind of sobriety test is estimated to be at 88% in determining if a driver’s BAC is 0.08% or more.

Walk and Turn Sobriety Test – WAT

This is a kind of attention dividing test. It involves having the subject focused on physical and mental tasks simultaneously. This sobriety test has various names, such as:

  • Nine steps walk and turn
  • Nine-step field sobriety test
  • Walk the line sobriety test (DUI)
  • The straight-line sobriety test (DUI)

According to the NHTSA, the test is 79% accurate in determining the blood alcohol content of the driver. If the driver has poor focus, chances are their BAC is at 0.08% or over.

When the officer is administering this test, they expect the driver to remember and follow the given instructions. The physical movements a driver is subjected to involve:

  • The use of an imaginary or real line to take nine steps that are toe -to- heel
  • A sudden turnaround
  • And repeating the same toe to heel steps backward

During the administration of the test, the police will be on the lookout for eight specific signs that will show if the driver is impaired. The officer will be observing to see:

  • If the driver can maintain balance as they follow instructions
  • Starts to walk too soon
  • If when walking he or she makes stops
  • If the driver is unable to touch his toe to a heel
  • If the driver goes off the real or imaginary line
  • If the driver will try to use their hands to find balance
  • If the driver has challenges turning
  • If the driver takes more or less of the steps instructed

One-Leg Sobriety Test

This is another kind of attention dividing test of the three tests used in the field to establish if a driver is sober or drunk. When the officer is administering this test to a driver, they will instruct him or her to:

  • To raise their foot from the ground at approximately six inches
  • To hold that position for some time without any movement at all
  • Start counting from 1001 to 1030
  • Turn their gaze and look at their foot.

While the driver is following the officer’s instructions, the officer will be on the lookout for clues that will indicate whether the driver is intoxicated or not. Some of these clues include:

  • Is the driver swaying from one side to the other
  • Is the driver using their hands to maintain balance
  • Does the driver hop
  • Is the driver unable to keep their raised foot and keeps dropping it down?

When a driver displays at least two of the clues above, there is a chance they are impaired. The test has an accuracy of 83%, meaning showing any of the above clues may be an indication that the driver’s BAC is 0.08% or more.

The above-discussed sobriety tests are standardized, according to NHTSA. However, various sobriety tests are not standardized, yet they are used to establish if the driver is drunk driving.

Non-Standardized Field Sobriety Tests

Aside from the above discussed standardized field sobriety tests, law enforcement officers, while conducting DUI investigations, use a variety of other tests in California. However, these tests often have no correlation with DUI impairment, meaning their accuracy is not as high.

It is even worse when the procedure of administering these tests vary from one cop to the other. This makes their legitimacy, as well as their accuracy questionable. Here, we discuss some of these tests that may be administered to you should you be stopped for suspected drunk driving.

Hand Pat Sobriety Test

This is another type of attention divided test when investigating a DUI. This test involves the suspect patting their hand, alternating the action while counting. The driver is expected to:

  • Extend their hand out with the palm upwards. Then the other hand is placed on it with its palm facing downwards. Using the upper hand, the suspect should start patting the hand at the bottom.
  • As the upper hand is patting, it should be making 180-degree movements that cause it to alternate between its back and its palm, while the bottom hand is stationary.
  • With every pat, the suspect must count audibly, repeating one and two

When administering this test, a law enforcement officer is normally on the lookout for four things that will help determine if the suspect is driving drunk or sober. Some of the things they look out for include:

  • If the DUI suspect is able to adhere to instructions
  • If the DUI suspect is able to keep counting correctly
  • How the sequence and rotation of the suspect’s hand while patting is maintained
  • The timing when the DUI suspect begins and ends the test.

Finger-to-nose Sobriety Test

This sobriety test is ancient in California. When administering this test, the suspect is expected to:

  • Tilt their head slightly backward and with their eyes closed, touch their nose at the tip with their index finger also at its tip
  • Repeat the movement with alternating hands as the law enforcement officer instructs. This is done six times, mostly each hand repeating the movement three times.

When the officer is administering this sobriety test, he or she is looking for various signs that will help determine if the suspect is impaired. These signs include:

  • The ability of the DUI suspect to adhere to instructions
  • The direction and amount the DUI suspect sways
  • If the tremors the suspect develops on their body or legs as well as the eyelids
  • The tone of the suspect’s muscle
  • Strange noise or words from the suspect as they carry on the test
  • How deep the suspect’s perception is
  • If the suspects touch their index finger to the nose or the face instead

Rhomberg Balance Sobriety Test

This kind of test checks on the internal clock of the DUI suspect. During the test, the law enforcement officer instructs the suspect to do the following:

  • Stand while their feet are put together
  • Tilt their head to the back slightly
  • Have their eyes closed
  • Estimate when thirty seconds are past
  • When they are sure the time has elapsed (30 seconds), the suspects then tilt their head forward and opens their eyes. They then say stop.

The law enforcement officer, when administering this test, is looking to determine if the suspect is intoxicated or not. To establish this, the officer is looking at various signs. These are:

  • How much the DUI suspect sways and to what direction
  • The estimated time passage by the suspect
  • The level of tremors from the suspect’s eyelids or body
  • How the suspect’s muscle appear, are they flaccid or hard
  • Whether or not the DUI suspect can adhere to instructions

Finger Count Sobriety Test

When you get pulled for suspected drunk driving, the law enforcement officer may decide to test your sobriety with this kind of test. The cop will ask you to:

  • Extend your hand and have your palm facing upwards
  • Using the thumb, touch its tip to the tips of the other fingers one at a time
  • As you touch the fingers to the thumb, you will be counting from one to four with each connection between your thumb and fingers.
  • Repeat the process, making a set of three repetitions.

As the officer is administering this test, he or she is looking for various signs as listed below to establish whether or not you are intoxicated. These are:

  • Are you able to adhere to instructions
  • Are you able to count properly
  • Are you able to sequentially touch your thumb to each finger
  • Are you able to begin and end the test as asked
  • Are you able to perform the three sets as requested by the officer

Conditions that Affect the Accuracy of Field Sobriety Tests in the Field

Various situations in the field can make the tests unnecessarily difficult to carry out. The law enforcement officers are expected to ensure the conditions for testing are suitable, but sometimes they fail to ensure this.

According to the NHTSA, the standardized field tests should be carried out under safe and appropriate conditions. As earlier discussed, the standardized tests include walking and turning tests, standing on one leg test, and the HGN test.

Although there is no provision for standard procedures while administering non-standardized tests, they are still given, but the jury or courts need to establish that the conditions were reasonable and fair. Some of the conditions that would interfere with the accuracy of these tests are:

Surface Conditions

A sobriety test should not be carried out where the suspect is at risk of falling. The surface for carrying out these tests should be hard, dry, non-slippery, and level. Space, where the suspect will carry out the test, must be adequate to enable the proper performance of the test.

The police are always advised to take the DUI suspect to a different location if the guidelines at the place one was pulled over cannot be adhered to.

Lighting Conditions

Lighting is another condition that can affect the validity of these tests. Adequate lighting is essential for both the suspect and the officer to see the ground and the surrounding well. When there is insufficient lighting, an officer can provide lighting to the ground using a flashlight. Darkness, in many cases, interferes with the ability of a suspect to perform the test even when they are sober.

Auditory Conditions

Noise can cause a suspect not to hear what the officer is saying or the instructions being passed down. If the location is filled with disruptive noises like sirens or honking, communication might be a challenge between the officer and the suspect. In such a case, the cop should move the suspect to a better location.

Accuracy Level of Sobriety Tests

The NHTSA carried out various field studies in the 1990s to determine the accuracy of various sobriety tests carried out in the field. In Colorado, the tests were carried out in 1995 in San Diego in 1998 and in Florida in 1997.

The NHTSA concluded that various sobriety tests conducted in the field and the subsequent arrests were correct according to the legal BAC. In Colorado, the accurate arrests made from these tests were at 86%, in California at 91% while in Florida at 95%.

However, the NHTSA insists that the high correlation applies when:

  • The officers carry out the tests according to how they are prescribed and standardized
  • The use of standardized clues in assessing the performance of the suspect
  • The criteria to interpret the suspect’s performance is the standardized one

How Sobriety Test Results are Challenged During a DUI Defense

Irrespective of the claims by NHTSA, the accuracy of the sobriety tests are not always as claimed. If you are facing DUI charges because of these results, your experienced lawyer could help fight these allegations by challenging the sobriety tests.

Some of the most common reasons why sobriety tests carried out in the field may be inaccurate include:

Mental or Physical Conditions – a person can be suffering from various psychological as well as physical conditions that can cause them to fail a sobriety test. Some of these conditions may include:

  • Age of the driver, those at 60 years or more may have physical challenges
  • The suspect could be suffering from foot, back or leg issues
  • The suspect may be suffering from hearing difficulties
  • When the suspect is obese may find it challenging to perform some tests
  • The driver could be sick either physically or mentally, making it a challenge to adhere to instructions.

Unsuitable Clothing – the performance of a suspect when carrying out the test can be   affected by their attire. A person wearing very high shoes, tight shoes or pants, beltless pants, gloves, among others, may find it challenging to carry out a sobriety test.

Officer Environment – any slight movement can affect the validity or accuracy of the sobriety test. An officer is expected to be stationary with no distracting behaviors as he or she administers the test. This is, in most cases, is impossible, and the results can be tainted.

Wrong timing – some of these tests require accurate timing. If an officer fails to use a watch to time a test, begins or terminates the test at the wrong time, it can affect the results of the test.

Environmental conditions – these sobriety tests are conducted on the roadside, and to enhance their accuracy, and certain conditions must be met. When the conditions are not met or are adverse, the results can be invalidated. Some of the requirements include:

  • Inadequate lighting
  • Uneven surfaces
  • Prevailing weather conditions
  • Disturbance from passing traffic, spectators among other distractions.

Non-standardized tests – the only standardized sobriety tests are three, according to the   NHTSA. However, non-standardized sobriety tests that lack guided procedures can result in inaccurate results.

Other Causes for Test Failures – lack of coordination is not always caused by alcohol or drug intoxication. If a suspect fails, the officer can assume the suspect to be intoxicated while other reasons such as lacking proper sleep, dehydration, medication, muscle strains can cause the failure.

Vague Instructions – sometimes, the officer can fail in giving clearly understood instructions failing the test.

Can One Refuse to Take a Sobriety Test?

The law does not compel a driver to take a sobriety test when asked to in the field. It is recommended to decline to take the test politely. Most sobriety tests are designed for the driver to fail, and taking them strengthens the officer’s resolve to arrest you.

Find a DUI Lawyer Near Me

A conviction on a DUI charge can bring penalties that one is not ready for. Even when you have taken a sobriety test and failed, you need proper legal representation to fight against the allegations as a result of these tests. At The DUI Defense Attorney, we are experienced and ready to fight these allegations on your behalf. Call our Van Nuys DUI Attorney today at 818-253-1913, and we will make an appointment to discuss your case.