The Only 3 Effective DUI Field Tests

Police officers use field sobriety tests (“FSTs”) when they stop a driver suspected of being under the influence of drugs and/or alcohol. The three standardized field sobriety tests (“SFSTs”) are considered the most reliable FSTs and the tests recommended by the National Highway Traffic Safety Administration for use by law enforcement agencies. However, police officers also use non-standardized field sobriety tests. Unfortunately, all tests have potential issues that can make the results unreliable.

The Purpose and Types of DUI Field Sobriety Tests

How do police officers use field sobriety tests during DUI investigations in California?

California uses the three standardized field sobriety tests to conduct DUI investigations during traffic stops. The purpose of conducting the tests is to determine whether a driver is impaired. The tests also serve to provide probable cause for a DUI arrest. A police officer must have probable cause to believe the person is intoxicated before making a lawful DUI arrest.

Three tests were chosen as standardized field sobriety tests. Each test has specific instructions and procedures for giving the test to a driver. Any deviation from the procedures could make the test results inaccurate and unreliable. Those three tests are: (1) Horizontal Gaze Nystagmus Test (“HGN”); (2) Walk and Turn Test (“WAT”); and (3) One-Leg Stand Test (“OLS”).

Horizontal Gaze Nystagmus Test (“HGN”)

The Horizontal Gaze Nystagmus Test checks for involuntary “eye jerking” or nystagmus, which occurs when a person looks to the side without turning their head. The severity of the “jerking” increases when a person is intoxicated. An HGN test can also detect when a person has consumed certain prescription medications and illegal drugs.

The police officer performs the test by instructing the person to focus on a stimulus, which is usually a small object, finger, or pen. The officer moves the stimulus horizontally across the person’s line of sight about a foot to 15 inches away. As the driver’s eye follows the object, the police officer watches for signs of increased nystagmus including:

• Inability to follow the object smoothly;
• Distinct jerking at maximum deviation; and
• Substantial eye jerking within a minimum of 45 degrees from the center.

The officer looks for the signs in each eye, checking for six total signs of increased nystagmus.

Walk and Turn Test (“WAT”)

The Walk and Turn Test is the test most people are familiar with due to its depiction in movies and television. During the WAT, a police officer instructs the driver to take nine steps along a straight line, turn around, and then take nine steps back to the starting point. The steps must be heel-to-toe steps.  The officer instructs the driver to count the steps out loud as they take each step. The officer watches for eight indications that the person might be impaired:

• Inability to balance while listening to instructions;
• Making an improper turn;
• Beginning to walk before the officer instructs the person to begin the test;
• Taking the wrong number of steps;
• Stopping to regain balance while walking;
• Stepping out of line;
• Failing to touch the heels to the toes; and
• Using the arms for balancing.

The standardized instructions state that if the person displays at least two of the eight indicators, they fail the walk-and-turn test.

One-Leg Stand Test (“OLS”)

The police officer instructs the person to stand still and lift one foot off the ground about six inches. The officer instructs the person to count by one until the officer tells them to stop while holding their foot off the ground. The standardized instructions state the officer should time the suspect and stop them in 30 seconds. The officer looks for four indicators of impairment:

• Hopping during the test;
• Repeatedly swaying during the test;
• Putting their foot down one or more times; and
• Using the arms to maintain balance.

The standardized instructions state that committing two or more of the four indicators means the person failed the one-leg stand test.

Field Sobriety Tests: Potential Problems and Challenges

Even though the above tests are widely considered reliable indicators of driving under the influence, there are many problems with the tests. Critics cite issues with the accuracy and reliability of test results. They also question environmental factors and the actions of police officers that could result in flawed test results.

What Do the Tests Mean if You Fail?

The police officer should refer to their FSTs training to determine if the person “failed” a field sobriety test. As indicated above, specific instructions in the training materials indicate when a person has “failed” the test.

If the officer decides that you failed one or more of the FSTs, the officer will likely state they have probable cause for a DUI arrest. The officer may then ask the driver to take a preliminary alcohol screening (“PAS”) test, which is generally a field breathalyzer machine. A BAC (“blood alcohol content”) level on the breathalyzer gives the officer additional probable cause to make an arrest for DUI.

After a lawful DUI arrest, California’s implied consent laws require individuals to take a chemical test. The police officer should ask the person whether they want to provide a sample for a breath test or a blood test for chemical testing. Urine tests are only used when blood and breath tests are unavailable.

Field Sobriety Tests: Accuracy, Limitations, and Criticism

There are limits to using field sobriety tests during a DUI stop. There are also questions regarding the accuracy of field sobriety tests. Some of the issues that DUI defense attorneys raise regarding the use of FSTs in DUI cases include:

• The accuracy of field sobriety tests;
• Failing to provide clear and correct instructions;
• Environmental factors;
• Medical conditions;
• Being nervous &/or scared; and
• The subjectivity of SFSTs.

The Accuracy of Field Sobriety Tests

Several studies have been conducted on the accuracy of FSTs in determining whether a driver is impaired by alcohol and/or drugs. The NHTSA Instructor Guide for the tests explains that three studies were conducted between 1995 and 1998. The studies were conducted in San Diego, Florida, and Colorado. Each study resulted in different conclusions regarding the accuracy of FSTs.

The Instructor Manual states that officers should use the San Diego Field Validation Study when testifying in court. That study indicated the following accuracy rates:

• HGN tests were 88% accurate;
• OLS tests were 83% accurate; and
• WAT tests were 79% accurate.

Even though the NHTSA claims that the study results provide clear evidence of the validity of standardized field sobriety tests, California DUI defense lawyers disagree. First, these tests are not 100% accurate. Moreover, other scientific tests have shown that the accuracy of these tests is questionable.

One study used sober individuals to perform standardized FSTs. After watching videos of people taking the tests, police officers believed that a significantly larger number of the people were impaired. Another study concluded that the HGN test has a high baseline error and varied greatly depending on whether the person’s BAC level was rising or falling. In 52 videos of DUI arrests, the study authors concluded the HGN test was incorrectly administered 51 times.

Additionally, other factors make the accuracy and validity of the tests questionable.

Failing to Provide Clear and Correct Instructions

The police officer administering the SFSTs must follow the exact procedures for giving the test to a driver. Deviation from the procedures could result in inaccurate results. However, suppose there is no body camera footage, other video footage, or audio evidence that the officer gave the person clear and correct instructions. In that case, there is no way to know if the officer purposefully or unintentionally caused the person to “fail” the field sobriety test.

Environmental Factors

Numerous environmental factors could invalidate the results of standardized field sobriety tests. For example, the officer should conduct the tests on a level, paved surface. Otherwise, the person may stumble or lose their balance because of the ground, but not because they are impaired by alcohol. Another example is conducting the HGN test with bright lights shining in the person’s eyes from the sun or oncoming traffic. The lights could cause unreliable results.

Medical Conditions

Another problem to consider is the person’s health condition. A person may have a medical condition that prevents them from passing the test even though they are sober. In addition, a person’s age could cause them to perform poorly on a test even though they are perfectly capable of operating the motor vehicle safely. Physical limitations may prevent someone from “passing” the one-leg stand test or the walk-and-turn test.

Some medications could cause a person to exhibit signs of intoxication even though they are sober and not impaired. For example, some medications for seizures can cause increased nystagmus even though the person is sober. In addition, there are dozens of other possible causes of nystagmus, including hypertension, eye strain, glaucoma, and consuming excessive amounts of caffeine.

Being Nervous and Scared

Merely being nervous about being pulled over and scared of being arrested could cause someone to perform poorly on SFSTs.

SFSTs are Subjective

Whether you fail or pass a sobriety test depends upon the officer’s interpretation of your performance during the tests. In other words, one officer might conclude you were intoxicated and arrest you for drunk driving. Another police officer might conclude that you are not impaired and release you without an arrest. A study conducted using police officers, bartenders, and university community members found that the group had less than a 25% accuracy rate when correctly determining how drunk a person was after observing the targets for several minutes. Furthermore, the accuracy of the ratings worsened as the targets’ level of intoxication increased.

If a police officer has some bias against the person, the officer might unethically or unconsciously interpret the results in favor of probable cause and an arrest. For example, a driver was rude and obnoxious when the officer made the initial traffic stop. The person was critical and uncooperative. In that case, the officer might decide that the person is drunk and make the arrest, even though the results of the SFSTs were borderline.

Non-Standard Field Sobriety Tests

Some jurisdictions also use non-standardized field sobriety tests to determine impairment to support probable cause for a DUI arrest. Police officers claim the non-standard FSTs are reliable because they require the person to utilize split focus and dexterity, which is difficult to do if the person is drunk or drugged. However, these non-standardized tests are unreliable and highly subjective. Some non-standard field sobriety tests used by police officers include:

• Romberg Balance Test – Closing the eyes and tipping the head backward while standing with the feet together, estimating when 30 seconds have passed, and then saying “stop” to the officer.
• Finger-to-Nose Test – Closing the eyes and touching a finger to the tip of the nose.
• ABC Test – Reciting the alphabet forwards or backward.
• Finger-Tap Test – Tap a finger to your thumb as fast as possible with an opening between taps as wide as possible.
• Numbers Backward Test – Counting backward.
• Stand and Gaze Test – Standing and leaning so that the person gazes at the sky while holding their arms to their sides.
• Hand Pat Test – Extend an arm out with the palm facing up and out. Place the other hand on top of the raised palm facing down. Rotate the hands 180 degrees to pat the bottom hand with the back of the other hand before rotating and doing it again while counting “one” and “two” each time.

The NHTSA does not recognize these tests as reliable indicators of whether a person is impaired by alcohol and/or drugs. A skilled California DUI defense attorney will challenge these test results in court. Challenging non-standard field sobriety tests is easier because they are not widely accepted as accurate indicators of intoxication or impairment.

Field Sobriety Test Refusals – Drivers Aren’t Required to Participate in Field Sobriety Tests

No California law punishes a person for refusing to take a field sobriety test. However, a police officer will not tell you this detail. Instead, the officer will only ask you to perform the tests without indicating that you may refuse the test without punishment. Understanding your right to refuse to take a field sobriety test is essential because sober people can fail the tests.

However, there is a difference between field sobriety tests and chemical tests for BAC levels. California’s implied consent laws require drivers to submit to a chemical test of their blood or breath after a lawful DUI arrest. Refusing a chemical test after a DUI arrest results in an administrative driver’s license suspension by the California Department of Motor Vehicles (“DMV”). Your driving privileges are suspended for one year for a first-time refusal of a chemical test. A second refusal within ten years results in a two-year revocation of your driver’s license.

However, if you are under 21 years old or on probation, refusing a chemical test after a DUI arrest of a preliminary alcohol screening (“PAS”) test after being detained results in a one-year driver’s license suspension for the first refusal and two-year revocation for a second refusal within ten years.

California Vehicle Code §23612 states that an officer must advise you that refusing the chemical test could result in a suspension of your driving privileges. Your California DUI attorney might be able to successfully argue against the DMV administrative license suspension if the officer failed to provide the required advisements.

How Field Sobriety Test Results Are Used in Court & Challenging FSTs Results in California

The prosecution uses the results from field sobriety tests in court in several ways. First, the prosecutor may use the FSTs to support the finding that the police officer had probable cause to arrest you for driving under the influence.

If you are charged with driving under the influence, the prosecutor uses field sobriety tests to support the allegation that you were too impaired to drive. This situation often occurs when the driver refuses to take a chemical test. The state does not have evidence of the BAC level at the time of the arrest. Therefore, it must prove that your ability to operate the vehicle was impaired.

When you are charged with DUI per se, the state has BAC test results showing that you were driving with a BAC over the legal limit. Generally, the BAC test results are sufficient to prove the state’s case if there is no valid DUI defense to convince the jury you were not drunk or under the influence of drugs. However, a prosecutor might use the FSTs results as additional evidence you were drinking and driving.

A skilled California DUI lawyer challenges the results of standardized FSTs in court. The attorney might challenge the results in one of several ways including:

• Challenging the reliability of the tests based on data showing a considerable margin for error. The attorney might hire an expert witness to provide testimony regarding the accuracy of the test.
• Providing evidence that the law enforcement officer failed to administer the standard FSTs according to the procedures in the NHTSA manual.
• Offering evidence proving that the test results were negatively impacted by a medical condition, legal prescription medications, or environmental factors.
• Your clothing, lack of sleep, muscle fatigue, advanced age, injuries, weight, or other extraneous conditions caused poor performance on the FSTs.
• The officer administered non-standardized field sobriety tests.

There could be other challenges and DUI defenses in your case. Schedule a free consultation to talk with a DUI lawyer about potential defenses to drunk driving charges.

Talk to a California DUI Defense Attorney

Fighting DUI charges begins with hiring an experienced DUI defense attorney. Contact a criminal defense lawyer for a free consultation to discuss your case. Most attorneys offer a free consultation so that you can get answers to your questions about DUI defense and your legal rights to make an informed decision about how you want to proceed with your DUI case.

Schedule a free consultation with one of our expert California DUI attorneys here.

Interested in this topic or want to learn more about DUIs in California? Check out our blog, which is updated regularly!

Sources:

https://www.ojp.gov/ncjrs/virtual-library/abstracts/standardized-field-sobriety-testing

https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/sfst_ig_refresher_manual.pdf

https://pubmed.ncbi.nlm.nih.gov/7991338/

https://pubmed.ncbi.nlm.nih.gov/11393940/

https://psycnet.apa.org/record/1984-12497-001

https://www.dmv.ca.gov/portal/driver-education-and-safety/dmv-safety-guidelines-actions/driving-under-the-influence/

https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=23612

Driving under the influence in California has immediate and long-term consequences. After a DUI arrest, the police officer seizes your driver’s license. In addition, depending on the circumstances of your arrest, the police officer may impound your vehicle after a DUI arrest. 

After your car is impounded, understanding your legal rights can help you get your car back quickly. However, be prepared to pay an impound fee and possibly install an ignition interlock device (IID) if you want to continue driving on a restricted driver’s license.

When Do Police Officers Impound Vehicles After a DUI Arrest?

If a police officer arrests you for drunk driving, the question arises of what to do with your vehicle. Leaving a vehicle on the side of the road is rarely an option. California Vehicle Code §22651 gives police officers authority to remove vehicles if they take you into custody. 

Generally, police officers are required to have vehicles towed to the police impound lot when:

• Your vehicle is evidence or part of a crime scene (i.e., a DUI accident involving injuries or fatalities)
• The vehicle’s condition does not permit someone to drive it safely 
• There are no nearby locations to park and leave your car legally and safely
• You have prior DUI convictions on your driving record during the past ten years

However, a police officer may not automatically impound your car if you have a prior DUI. The officer might not take the time to review your driving history during a DUI traffic stop. Instead, the officer might focus solely on the current drunk driving offense. 

If the law does not require a police officer to impound your vehicle, your attitude during the DUI stop can significantly impact the officer’s decisions regarding vehicle impoundment. 

The police officer may allow a sober passenger to drive the vehicle. Officers might pull your vehicle to a safe location at a DUI checkpoint. However, someone must pick up your vehicle before the end of the DUI checkpoint. Generally, only the registered owner can pick up a car at a DUI checkpoint. However, the officer might allow you to designate someone to pick up your vehicle if you are the registered owner.

An officer could offer to drive your vehicle a short distance to a parking lot or other safe location. However, if you are belligerent, disrespectful, and uncooperative, the officer is unlikely to “see” a safe parking location nearby the traffic stop.

Can the Court Impound My Car After a DUI Arrest in California?

Yes, the court may impound your vehicle as part of the DUI penalties. For a first-time DUI conviction, the judge may order your car to remain in the impound lot for up to 30 days or not at all. A second DUI results in impoundment for up to 30 days. After three or more DUIs, the court can impound your vehicle for 90 days.

Having your vehicle impounded after a DUI in California is expensive. Whenever possible, try to avoid impoundment by politely asking the police officer if there is a way to have your vehicle parked or someone pick it up to avoid the impound lot. 

Another way to avoid a long impound period is to agree to install an ignition interlock device (IID). It may be expensive, but you might be able to continue driving if you qualify for a restricted driver’s license with IID installation. 

While asset forfeiture is not common, it can happen as part of a DUI case. When your vehicle is used to commit a crime, the law states that you can lose ownership of your car (asset forfeiture). In a DUI case, forfeiting your car generally only occurs if:

• The court declares your vehicle a nuisance because you have numerous DUI convictions within seven years
• You were involved in a DUI accident that resulted in a traffic fatality
• Your drunk driving arrest involved illegal drugs, especially if the police officer seizure illegal drugs from your car when they searched it

Seeking legal advice from an experienced California DUI defense lawyer as soon as possible after an arrest is in your best interest. A DUI attorney reviews your case and advises you of your legal options for fighting DUI charges and vehicle impoundments or forfeitures. 

What Should I Do if My Car is Impounded After a DUI in California?

Acting fast can save you money after the police impound your car. You pay a fee for each day your car remains in the impound lot. The longer you wait to reclaim your vehicle from an impound lot, the higher the fees are to reclaim your vehicle.

To get your car back after a DUI impoundment, you need:

• Proof of vehicle registration showing you are the registered owner
• Proof of required liability insurance 
• Your temporary driver’s license or Notice of Suspension
• Payment for all fees and costs charged for the impound, including fees for towing, daily storage, indoor storage, lien, and after-hours charges

You cannot retrieve your car until the police or the court release the vehicle from impound. The state only releases impounded vehicles to their registered owner. Therefore, if someone else was driving your vehicle, you do not need to wait to retrieve your car. However, you are responsible for paying the impound fees.

Some drivers may not be able to pay the fees to get their vehicles out of impound. Long impound periods could result in fees totaling more than a vehicle is worth. If you do not pick up your car from impound, your car may be sold at auction to pay the impound fees. Check with a California DUI attorney to determine the deadline for picking up your vehicle from impound after a DUI arrest.

What Happens to You After a DUI Arrest in California?

The police officers transport you to jail after a DUI arrest. California Vehicle Code §23152 makes it unlawful to:

• Drive a passenger vehicle with a BAC level of .08% or higher
• Operate a commercial motor vehicle or a vehicle with a passenger for hire in the car with a BAC of .04% or higher
• Operate a motor vehicle while under the influence of alcohol
• Drive a motor vehicle under the influence of any drug
• Operate a motor vehicle under the influence of a combination of any drug and alcohol 

A police officer initiates a traffic stop if the officer has probable cause to believe a crime is being or has been committed. For example, the officer may pull you over if he witnesses driving behavior that indicates you might be impaired by alcohol and/or drugs. However, the officer may also pull you over for a traffic infraction.

If the police officer suspects you are impaired during the traffic stop, he may request that you take a pre-assessment screen test, such as a roadside breathalyzer or cheek swab. You can refuse field sobriety tests and roadside preliminary alcohol screening (PAS) tests without penalty. 

However, California’s implied consent law requires you to take a chemical test to determine your blood alcohol content (BAC) level after an arrest for drunk driving. Refusal to submit to chemical testing after a DUI arrest can result in additional jail time and a longer duration for DUI school. 

Refusing a chemical BAC test after a DUI arrest results in an automatic license suspension. You cannot receive a restricted driver’s license at any time during the license suspension period for refusing a chemical test.

What Are the Penalties for a Drunk Driving Conviction in California?

The sentence for a DUI conviction depends on your prior DUI history and whether there are aggravating factors involved in your drunk driving case. 

DUIs are priorable criminal offenses in California. Therefore, the severity of the penalties for each subsequent DUI conviction within ten years increases. A felony DUI conviction can be counted against you regardless of when you were convicted. 

Aggravating factors can also increase the severity of DUI punishments. Aggravating factors that enhance a DUI sentence include, but might not be limited to:

• Having a high BAC level (generally .15% or higher) at the time of your arrest
• Being under 21 years old at the time of a DUI arrest
• Having a minor under 14 years of age in the car while driving under the influence
• Excessive speed (i.e., driving 20 miles per hour or more over the posted speed limit)
• Causing injuries or death while driving under the influence 
• Refusal to submit to a chemical test
• Driving under the influence while on DUI probation

Assuming that this is your first DUI conviction and there were no aggravating factors to enhance the DUI sentence, the judge could punish you with:

• Six-month loss of driving privileges
• Fines and assessments of up to $2,000
• Up to six months in county jail
• Attending DUI school for three to nine months
• Summary (informal) probation for three to five years

The court may also require you to install an ignition interlock device (IID) for up to six months. 

You can fight DUI charges with the help of a California DUI lawyer. Violations of your civil rights, lack of probable cause, challenges to BAC tests, and violations of Title 17 are just a few DUI defenses that could beat DUI charges.

The first step is to seek legal advice from a trusted, experienced DUI defense attorney in California. 

No, California law enforcement officers do not need probable cause to stop a motorist at a DUI sobriety checkpoint. You could get arrested legally at a DUI sobriety checkpoint without the officer having probable cause to stop you.

You could, however, challenge the arrest if the checkpoint did not meet all the legal requirements our state law imposes on DUI sobriety checkpoints. A California DUI attorney can talk with you and examine whether a dismissal of the charges could be possible.

The Requirements for a DUI Sobriety Checkpoint to be Legal Under the California Constitution

In the 1987 case of Ingersoll v. Palmer, the California Supreme Court compared sobriety checkpoints to other administrative inspections, like airport screening searches. The Court held that law enforcement officers do not have to follow the 4th amendment at DUI roadblocks because these are administrative inspections, not searches and seizures.

The Court explained its decision to treat sobriety checkpoints as administrative inspections, not as searches and seizures, because “the primary purpose of the stop here was not to discover evidence of a crime or to make arrests of drunk drivers but to promote public safety by deterring intoxicated persons from driving on the public streets and highways.” 

As such, the California Supreme Court said that sobriety checkpoint stops do not require an individualized suspicion of wrongdoing. Instead, the Court said that the California constitution requires balancing the intrusiveness of the detention against the governmental interests.

Other Types of Regulatory Inspections and Stops

The Court in Ingersoll gave several examples of regulatory inspections in the stops that are legal according to the United States Supreme Court and California courts without the need for an individualized suspicion of wrongdoing. These include:

• Border Patrol or immigration checkpoint inspections
• Agricultural inspection checkpoints
• Vehicle mechanical inspections
• License and registration inspection checkpoints

The California Supreme Court in Ingersoll said that DUI sobriety checkpoints create a lesser intrusion on the individual’s 4th amendment interests than Border Patrol or immigration checkpoint inspections because, during the brief sobriety detention, neither the vehicle nor the occupant gets searched. The driver only needs to answer a question or two and possibly show the officer one’s driver’s license, registration, and proof of insurance.

The Justification for California DUI Sobriety Checkpoints

Law enforcement agencies across the United States have used a variety of approaches to try to address the drunk driving problem. Public awareness campaigns, increased patrols and arrests, and more severe penalties for DUI convictions have done little to tackle one of the most significant challenges, which is that the public knows that their risk of getting caught driving while intoxicated is quite low.

The California Highway Patrol (CHP) developed a pilot project of sobriety checkpoints in order to try to discourage people from driving after consuming alcoholic beverages. The CHP said they would rather deter drunk driving than have to make arrests and charge people with DUIs. The goal, according to law enforcement, is to decrease DUI arrests and alcohol-related accidents, not increase them.

Of course, when law enforcement officers break the rules and set up an illegal DUI sobriety checkpoint for the purpose of trapping unsuspecting drivers, there might be grounds for challenging an arrest.

California Supreme Court Created Functional Guidelines to Minimize the Intrusiveness of DUI Sobriety Checkpoint Stops

The Ingersoll court articulated eight requirements for legal DUI sobriety checkpoints in California. These guidelines are:

1. The typical law enforcement officer in the field cannot decide on his or her own to set up a sobriety checkpoint. The risk of allowing that conduct is the potential for arbitrary and capricious enforcement of the law. Instead, supervisory or command-level law enforcement personnel are the only ones who can legally decide to use a checkpoint, select the location, and create the operational procedures. The upper-level law enforcement personnel must distribute detailed program regulations to the officers who will work at the checkpoint.
2. Officers in the field will have strict limits on their discretion when working at DUI sobriety checkpoints. An officer will not be allowed to decide to stop any particular driver or car without a legitimate basis for that decision. The field officers must use a neutral formula, for example, stopping every single driver who pulls up to the checkpoint or, in the interest of keeping traffic flowing, only stopping every 5th or 12th driver or some other neutral formula.
3. The sobriety checkpoint must not create an unsafe condition for motorists or officers. To minimize the risk of danger to drivers, passengers, and police, the law enforcement personnel must be clearly identifiable as officers. They must use clearly marked official vehicles. The checkpoint must have sufficient warning signs, signals, and lighting to create a safe environment. If traffic becomes backed up because of the randomized stops, the field officers can adjust the neutral formula or temporarily suspend making stops until traffic clears.
4. The location of the checkpoint must be reasonable. Because the governmental interest is to deter people from driving while impaired by alcohol, the supervisory law enforcement personnel who select the locations should choose sites that will be most effective in achieving that interest. In other words, sobriety checkpoints should be set up on streets that have a high number of alcohol-related arrests or accidents. 
5. A checkpoint must balance intrusiveness and effectiveness in terms of the time of day that the officers operate the checkpoint and how many hours the checkpoint will be operational. Safety is also an issue. A DUI sobriety checkpoint is more likely to be effective if it operates during the hours when people are more likely to drive while impaired by alcohol, for example, late at night and in the very early morning hours. Operating a checkpoint doing during those hours, however, could be more hazardous to motorists and officers.
6. Motorists need to be able to tell at a glance that the DUI roadblock Is official and authorized and is not operated by rogues waylaying unsuspecting motorists. The general public is wary of criminals who impersonate police officers. The roadblock should incorporate flashing lights, warning signs, and adequate lighting. The fact that it is a sobriety checkpoint should be highly visible. Uniformed officers and marked police vehicles must be present. The government agency must provide advance warning of a DUI checkpoint to minimize intrusiveness to motorists and to reassure them that the roadblock is legitimate.
7. Supervisory law enforcement personnel must promulgate detailed guidelines on the length and nature of the detention of the random drivers who get stopped in DUI sobriety checkpoints. The stops must be as brief as possible for the officer to ask the driver one or two questions and look for signs of intoxication. If the driver does not show symptoms of being impaired by alcohol, the driver should not be delayed any further from driving on down the road. When an officer observes signs of alcohol use, the officer can direct the driver to a separate area of the checkpoint for field sobriety tests. In the separate area, those officers would have to have probable cause to conduct further investigation. The incident would no longer be an administrative inspection, but rather, the constitutional protections around traffic stops and arrests would apply to the situation.
8. As mentioned earlier, the government agency must provide advance publicity. A DUI sobriety checkpoint without sufficient advanced publicity could be considered arbitrary and capricious and violate the constitutional rights of motorists. The general public should get informed that law enforcement will be conducting sobriety checkpoints at specific locations, dates, and times. This publicity would serve the governmental interest of deterring drunk drivers from using those streets. The ultimate goal of the warning is that people would do their driving at home, take a taxicab if they have had too much to drink, or choose not to drink to the point of impairment from alcohol before driving.

When police departments set up DUI sobriety checkpoints that violate one or more of these eight guidelines, a person arrested at such a stop might have grounds to ask the judge to dismiss the criminal charges. The enforcement of traffic law must comply with state and federal constitutional protections. Police officers must minimize intrusiveness on the lives of the general public.

Signs of Intoxication

Officers working at sobriety checkpoints in California are allowed to ask one or two brief questions of the people they briefly detain. The purpose of asking the questions is to give the police officer the opportunity to look for symptoms of alcohol impairment of the driver, including:

• Fumbling when trying to locate one’s driver’s license to show the officer
• Bloodshot or glassy eyes 
• Slurred speech when talking to the officer
• Smelling alcohol on the breath of the driver or in the vehicle

The police officer is not limited to these examples of intoxication symptoms. The officer can direct the driver to another area of the checkpoint for additional investigation as long as objective facts support probable cause or reasonable suspicion that the driver is impaired by alcohol.

What Happens if a Driver Does Not Cooperate with the Officer at a DUI Checkpoint

The consequences of refusing to comply with the instructions from a law enforcement officer at a DUI sobriety checkpoint depend on the point at which the driver does not cooperate. California law requires everyone who operates a motor vehicle on public streets to cooperate with DUI sobriety checkpoints. 

You will likely be charged with violating the traffic laws if you do not follow the directives of uniformed law enforcement at a legal California sobriety checkpoint. 

Because the checkpoint is an administrative inspection, not a regular traffic stop, taking a field sobriety test, breathalyzer, or other tests before getting arrested is optional. If you refuse, however, the officer will likely arrest you for DUI, at which point refusing a breathalyzer or similar test will get your license suspended automatically for one year, in addition to other consequences.

If you or someone you know is facing a DUI, a California DUI attorney can help to protect your legal rights and aggressively pursue the best possible outcome in your situation.

The holiday season is fast approaching and before you know it, law enforcement will be ramping up its efforts to catch drunk drivers. Their efforts will inevitably include saturation patrols and DUI checkpoints, but they might also include, as they’ve done in the past, an ad campaign encouraging motorists on the road to contact law enforcement if they suspect that another driver is under the influence.

If an anonymous caller tips off police that someone might be driving drunk, the officer has no personal knowledge of facts that would lead them to believe that someone is driving drunk. The officer is only going off of what the tip had said. The tip could be accurate, it could be a lie, or it could just be mistakenly inaccurate. An officer must have probable cause to stop a driver on suspicion of a DUI, and probable cause means that the officer has reasonable and trustworthy facts that the driver is drunk.

The question becomes: Can an anonymous tip give an officer the required probable cause to stop a driver on suspicion of driving under the influence?

The United States Supreme Court in 2014 concluded in the case of Navarette v. California that an officer can use an anonymous tip as the basis for a DUI stop.

In Navarette v California, a motorist was pulled over by California Highway Patrol after an anonymous tip. The anonymous tipster told the dispatcher that they had been run off of Highway 1 near Fort Bragg by someone driving a pickup truck and provided the pickup’s license plate number. As the CHP officer approached the pickup, they smelled marijuana and discovered four bags of it inside the bed of the truck.

Officers identified the occupants of the truck as brothers Lorenzo Prado Navarette and Jose Prado Navarette.

At trial, the brothers filed a motion to suppress evidence claiming that the officers lacked the reasonable suspicion needed to stop them, thus violating the Fourth Amendment of the United States Constitution. The judge, however, denied the motion. The brothers then pleaded guilty to transporting marijuana and were sentenced to 90 days in jail, but appealed.

At the appellate level, the court ruled against the brothers saying, “The report that the [Navarettes’] vehicle had run someone off the road sufficiently demonstrated an ongoing danger to other motorists to justify the stop without direct corroboration of the vehicle’s illegal activity.”

The brothers appealed again, this time to the United States Supreme Court. Once again, the court concluded that an anonymous tip alone can give law enforcement the justification to pull someone over on suspicion of driving under the influence.

In quoting the previous case of Alabama v. White, the Supreme Court said, “[U]nder appropriate circumstances, an anonymous tip can demonstrate ‘sufficient indicia of reliability to provide reasonable suspicion to make [an] investigatory stop.’”

In finding that the anonymous tip was reliably, the court relied on the fact that the caller claimed eyewitness knowledge of dangerous driving, the fact that the tip was made contemporaneously with the eyewitness knowledge of the dangerous driving, and the fact that the caller used 911 to make the tip (knowing that the call could be traced).

According to the Court, if the tip bears “sufficient indicia of reliability,” officers need not observe driving which would give rise to suspicion that a person was driving under the influence or even that the driver committed a traffic violation. They only need the unverified and unsupported anonymous tip. 

Does anyone else see the problem here?

Justice Scalia did and he voiced his concern in his dissent to the majority opinion in Navarette v. California.

 “Drunken driving is a serious matter, but so is the loss of our freedom to come and go as we please without police interference. To prevent and detect murder we do not allow searches without probable cause or targeted Terry stops without reasonable suspicion. We should not do so for drunken driving either. After today’s opinion all of us on the road…are at risk of having our freedom of movement curtailed on suspicion of drunkenness, based upon a phone tip, true or false, of a single instance of careless driving.”

Anonymous tipsters are not necessarily reporting on drunk drivers (they don’t know if who they’re reporting on is even drunk). Rather, they are reporting driving errors, any of which can be interpreted as drunk driving. Everybody makes mistakes while driving. In fact, it might be fair to say that no driving trip is perfect and that all driving trips, no matter how short or simple, contain some mistakes. This necessarily means that everyone on the road is a target of anonymous tipsters and anyone can be stopped on suspicion of DUI simply because someone else reported their mere driving mistake (even if they are not drunk).

Many people often ask whether a DUI checkpoint is entrapment. Some ask whether it is entrapment when an officer who parks his or her patrol vehicle outside of a bar or another alcohol-serving establishment and catches a drunk driver.

Unfortunately, the answer is no in both cases, and the misconception lies in the common use of the word “trap” and the mistaken belief that it applies to the legal definition of entrapment.

In the case of People v. West, the court defined entrapment as “the conception and planning of an offense by an officer and his procurement of its commission by one who would not have perpetrated it except for the trickery, persuasion, or fraud of the officer. Persuasion or allurement must be used to entrap.”

Like many things in law, this rather confusing definition was later refined by the court in People v. Barraza when it said, “[T]he proper test of entrapment in California is the following: was the conduct of the law enforcement agent likely to induce a normally law-abiding person to commit the offense?”

Simply put, entrapment is a defense when the officer forces someone to do something when that person would not have otherwise done so.

With a DUI, entrapment would occur if the police forced the driver to drink when they would not have done so or force the driver to drive when they would not have done so.

Neither is the case with DUI checkpoints or when an officer parks their patrol vehicle outside of an alcohol-serving establishment.

Although many people consider checkpoints to be “traps,” they do not fit within the legal definition of entrapment. If a drunk driver is stopped at a checkpoint, the officer has neither forced them to drink nor drive. If a drunk driver is stopped and arrested at a checkpoint, it’s because they chose on their own to drink and drive before the encounter with the officer. Similarly, if an officer spots a driver coming out of a bar, follows them out onto the streets, then pulls them over for a DUI, the officer has neither forced them to drink nor drive.

Additionally, in both cases, the officers had the legal right to be at the location where they were. DUI checkpoints time and time again have been held by numerous courts to be constitutional. In fact, in California, one of the requirements a DUI checkpoint must adhere to in order to be constitutional is that drivers must be allowed to lawfully turn away from the checkpoint (Yes, that’s right, drivers cannot be forced to go through a DUI checkpoint). When an officer parks outside of a bar, typically they are in a public space, such as a parking lot, where they have a right to be.

Having said that, just because a person is driving through a checkpoint or observed leaving a bar does not mean that the officer has a right to arrest them on suspicion of a DUI. The officer must have probable cause (the amount of evidence needed for an officer to make an arrest) to believe that a person is driving drunk before an arrest can be made.

At a checkpoint, the officer obtains the evidence (i.e. probable cause) needed to make an arrest by asking passing drivers whether they’ve had anything to drink, observing symptoms of intoxication, and, of course, breathalyzing drivers. Without additional evidence that a person is driving drunk, an officer cannot make an arrest.

Similarly, the mere leaving a bar does not give the officer probable cause that a person is driving drunk, although the officer may suspect the person is driving drunk. If, however, an officer observes a person commit a traffic violation after leaving a bar, they can be pulled over. The traffic violation stop can be used as a pretext to investigate for a DUI.

Can entrapment ever be used as a defense for a DUI? Consider the following.

A person goes to a bar to have a drink. Thinking that they might be over the legal limit of 0.08 percent blood alcohol content, they lawfully sit on a bench outside of the bar. A few minutes later, a police officer approaches the person and demands that they drive out of the parking lot. The person obliges, gets in their car, and drives away.  As the person drives away, the officer stops and arrests the driver for driving under the influence.

Because the driver drove as a result of the officer’s demand when they would not have otherwise done so, entrapment may be a defense for the driver.

While this scenario is uncommon, it has happened. However, in the vast majority of California DUI cases, unfortunately the defense of entrapment cannot be used.