​What Are Field Sobriety Tests?

Published On: October 29, 2022By

A field sobriety test is a set of tasks a police officer has a suspected drunk driver perform in order to indicate signs of drunk driving. Police officers arrest thousands of people for DUI every year in California. When an officer makes an arrest, they may ask the driver to do a field sobriety test—usually by the side of the road. However, these tests are not always accurate, and certain environmental and health factors may impact a driver’s performance.

If a police officer recently arrested you for DUI, one of your first calls should be to an experienced DUI defense attorney in your area. Your DUI Defense lawyer can safeguard all of your legal rights while your criminal case is pending. Moreover, your attorney can speak with you about the facts and circumstances leading up to your arrest and the arrest itself and determine if you are eligible to raise a defense to your charge.

Finally, your attorney can represent you at all criminal court hearings and trials in your case. In some instances, your DUI defense lawyer may be able to arrange a favorable plea deal with the state prosecutor handling your case. In contrast, at other times, your DUI lawyer could advocate for completely dismissing your DUI charge at trial. If you ultimately sustain a DUI conviction, your attorney can represent you at your sentencing hearing and work to minimize the legal and collateral consequences of your DUI. Don’t fight a DUI conviction alone get legal help today.

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What Are the Legal Standards for DUI?

Every state in the country has its own legal standards for DUI. These standards determine whether or not a driver is legally intoxicated under the circumstances. To determine intoxication, an arresting police officer may subject a driver to a Breathalyzer test—or some other type of chemical test, such as a urine test.

When passenger vehicle drivers have a blood alcohol concentration (BAC) of at least 0.08 percent, they are per se intoxicated under the law. Stricter legal standards apply to commercial vehicle drivers, including tractor-trailer operators, and minors drivers under 21. The BAC cut-off for a commercial vehicle driver is 0.04 percent, while the legal cut-off for minor drivers is a BAC of 0.01 percent.

Drivers who violate these legal standards may be subject to a DUI conviction. If they ultimately sustain a conviction on their charge, a judge could sentence them to various penalties, including harsh fines and jail time.

Who Has the Legal Burden of Proof in a Criminal DUI Case?

In a criminal court DUI case, the state prosecutor has the sole legal burden of proof. The individual the police officer arrests, called the defendant, does not need to prove anything in the case.

To establish that a criminal defendant is guilty of DUI, the state prosecutor must establish that they were operating a vehicle at the time of their arrest—and that their BAC exceeded the legal limit. To support that a driver was legally intoxicated while behind the wheel, a prosecutor may move to admit various documents into evidence at trial, including Breathalyzer, chemical, and field sobriety test results.

Common Field Sobriety Tests

Field sobriety tests are mental and physical exercises that police officers administer to drivers when they suspect a driver is under the influence of alcohol. When a driver performs poorly on one of these tests, it serves as a strong indicator that the driver is legally intoxicated. Therefore, the officer may use poor test performance to make an arrest.

In California, drivers do not have to take a field sobriety test if an officer requests one. They may decline to take the test without incurring any type of fine or penalty.

Some field sobriety tests are standardized, while others are unstandardized. Standardized tests are those that the National Highway Transportation Safety Administration (NHTSA) previously authorized.

Standardized Field Sobriety Tests

Standardized field sobriety tests include the horizontal gaze nystagmus test (HGN), the walk and turn test (WAT), and the one-leg stand test (OLS).

  • Horizontal gaze nystagmus is a jerking motion of a person’s eyes when they move their eyes to the side. When administering the test, the police officer tells the driver to follow an object with their eyes to the right and then to the left. The officer then measures the angle where the driver’s pupil starts showing nystagmus—or the angle where the involuntary eye jerking starts. When nystagmus occurs early—or before the angle is 45 degrees—it indicates a high blood alcohol concentration (BAC) level.
  • Walk and turn test. When a police officer administers a walk and turn test, the driver must take nine steps—heel to toe—along an imaginary or real line on the ground. The driver must then pivot their body and take nine steps heel to toe back to the starting location. The officer will watch the driver’s movements as they walk along the line. Indicators of alcohol intoxication include the driver’s inability to keep their balance while walking, beginning the test too quickly, stopping during the test, stepping off the real or imaginary line, an inability to walk heel-to-toe, taking the wrong number of steps, failing to turn the wrong way before switching directions and using their arms to balance themselves while walking.
  • One-leg stand test. When administering the one-leg stand test, the driver has to raise their foot to a level approximately six inches above the ground, hold that position, count from 1001 to 1030, and look down at their foot while counting. The officer will observe the driver’s movements and behaviors during the test. Common indicators of alcohol intoxication include bodily swaying, hopping, putting one’s foot back on the ground, or using arms for balance.

Non Standard Field Sobriety Tests

In addition to these NHTSA-approved field sobriety tests, some officers may use non-standard tests to gauge a driver’s sobriety at the scene.

These tests include:

  • The hand-pat field sobriety test
  • The finger count test
  • The Rhomberg balance test

Are Field Sobriety Tests Always Accurate?

Although field sobriety tests are often indicative of whether or not a driver is impaired or intoxicated, they are not always accurate. In fact, environmental factors and health conditions may cause a driver to perform poorly on a test.

Some of the most common external factors that may affect a test result include:

  • Surface conditions. For a field sobriety test result to be accurate, the officer must ordinarily administer the test on a surface that is non-slippery, hard, level, and dry. Moreover, the driver should have enough space to complete the test comfortably.
  • Lighting conditions. Moreover, to ensure that a field sobriety test result is accurate, the officer must provide adequate lighting. Specifically, the driver must clearly see the ground and the police officer. If the lighting conditions are too dark, the driver may not be able to complete the test accurately, even if sober.
  • Auditory conditions. For a field sobriety test result to be accurate, the driver must clearly hear the police officer’s instructions. Similarly, officers must ensure—to the greatest extent possible—that there are no noise disturbances in the vicinity, including sirens and honking horns.

Some of the most common health conditions that may produce an inaccurate field sobriety test result include:

  • The driver’s age, especially if over 60 years old
  • The driver’s weight, especially if they are overweight by at least 50 pounds
  • The driver suffers from leg, foot, or back problems
  • The driver suffers from mild brain damage
  • The driver is in physical pain
  • The driver suffers from a mental disability that affects their ability to comprehend basic officer instructions

Finally, a driver’s attire may prevent them from performing a field sobriety test correctly.

Articles of clothing that may inhibit their performance include:

  • Gloves
  • High heel shoes
  • Baggy pants
  • Boots
  • Shoes that are too tight

In some instances, a DUI defense lawyer could argue that a driver’s field sobriety test result is inaccurate due to one or more of these factors.

Other Defenses to a Criminal DUI Charge

The results of chemical tests and field sobriety tests are not infallible, and a defense lawyer may be able to challenge them under certain circumstances.

However, police officers may also violate a driver’s Fourth Amendment rights by initiating an invalid traffic stop. They may also violate the driver’s Fifth Amendment rights by continuing to question them after requesting an attorney.

When a defense lawyer raises a valid legal defense to a DUI charge in court, that defense may negate one or more elements of the charge, preventing the state prosecutor from establishing their legal burden beyond a reasonable doubt. Consequently, the DUI charge might then be subject to a complete dismissal by the court.

An experienced DUI defense attorney in your area will be able to determine if you are eligible to raise one or more defenses to your DUI charge. If you are, your lawyer can raise the appropriate defense on your behalf at a criminal court trial and work to obtain the best possible result in your case.

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What Are the Potential Penalties for a DUI Conviction?

When an intoxicated driver sustains a DUI conviction, they may face numerous legal and administrative penalties. Moreover, they may suffer various collateral consequences which affect them for the rest of their life.

If a state prosecutor obtains a DUI conviction against you, a sentencing judge will be left to impose various penalties. The penalties that an individual may incur for a DUI conviction depend upon several factors, including the amount of alcohol in their system, whether they have one or more prior convictions for DUI on their record, and whether they caused an accident with another vehicle or pedestrian which led to injuries or fatalities.

Some of the most common penalties that DUI offenders receive upon conviction include:

  • Jail time
  • Monetary fines
  • Required payment of restitution if property damage occurred
  • Probation
  • Loss or permanent revocation of a driver’s license
  • Mandatory participation in alcohol rehabilitation and counseling sessions

In some instances, a court may also require the offending driver to install an ignition interlock device (IID) on their vehicle. This device is a personal Breathalyzer machine that the driver must breathe into before starting their vehicle. If the device detects alcohol on the driver’s breath, it will not allow the vehicle to start. In addition to paying for initial installation fees, the driver must pay to maintain the device regularly, which may incur high costs.

In addition to these potential legal penalties, drivers may face numerous collateral consequences associated with their DUI conviction. Specifically, they may have trouble finding a place to live, getting into school, or finding a job. This is because landlords, educational institutions, and prospective employers routinely perform online criminal background checks on applicants. They may deny the individual’s application if they find a DUI conviction or other serious offense on the individual’s record.

An experienced DUI defense lawyer can work to minimize the potential legal and collateral consequences of your conviction. They can also represent you at all DMV and criminal court hearings and work to obtain the best possible result for you.

Speak With a Knowledgeable DUI Defense Lawyer as Soon as Possible About Your Pending Charge

If you are currently pending trial on a recent DUI charge, you must have experienced criminal defense lawyer representing you throughout your criminal case. On the other hand, not having legal representation can be a serious mistake. In fact, if you show up to your court hearing or trial without legal representation, a judge might assume that you are waiving your right to legal representation and make you represent yourself in court.

Having strong legal representation by your side throughout your DUI case can be extremely beneficial. First, it increases your chances of a favorable result in your case, either via a good plea deal or a favorable result at trial—such as a not guilty finding. This is especially true if you have a solid legal defense to your DUI charge—or when your lawyer can validly challenge chemical or field sobriety test results.

If you ultimately sustain a conviction on your charge, experienced legal representation increases your chances of getting a fair penalty. Your lawyer will aggressively advocate for you throughout your entire case, ensure that your legal rights remain protected, and pursue the best possible result that’s available in your circumstances. Find a DUI lawyer for your case today, click the button below and schedule a free consultation.

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