In California, it is illegal to operate a vehicle when your blood alcohol content or blood alcohol level exceeds .08%. A high content of alcohol in the blood is an indication that you are intoxicated. Driving under the influence (DUI) is a severe offense in California, and the penalties are detrimental. The penalties for driving under the influence may include imprisonment, fines, and license suspension, among others. San Diego DUI Attorney assists individuals facing charges for drunk driving to come up with a defense. For instance, if you are in La Presa, an experienced La Presa DUI Attorney can help you construct a viable legal defense against DUI charges.

Establishing Intoxication

For you to face DUI charges under California law, the prosecutor has to prove beyond doubt that you were driving a vehicle while intoxicated at the time of the arrest. To help determine whether a driver is intoxicated, the police use field sobriety tests and DUI testing procedures.

Field Sobriety Tests

In California, The National Transportation Safety Administration (NHTSA) issues policy guidelines and protocols for field sobriety testing. Law enforcement officers may use numerous field sobriety tests. The NHTSA has validated three sobriety tests as the most reliable. Some of the testing methods include:


Commonly abbreviated as OLS, the One-leg-stand is a standardized field sobriety test. The test helps to determine whether a vehicle driver has divided attention due to intoxication. When administering the test, the officers might request a driver to raise his or her foot from the ground. The driver might have to raise the foot for around six inches from the ground. The police will then require the driver to hold still and maintain the raised food while counting from 1001 onwards. The police might also request a driver to look down at his/her foot while still raising one leg.

The law enforcement officers are keen while administering this test to notice any signs of intoxicated. If a driver is under the influence of alcohol, he/she may sway while told to stand on one foot. A driver may also be unable to maintain balance and might have to use his/her arms for balance. Due to lack of balance, an intoxicated driver may hop around or put his/her feet or hands down. NHTSA states that if a driver exhibits two or more signs of intoxication during the administration of the OLS test, there is a high chance that the driver has a BAC that exceeds .08%.

Walk and Turn Test

Just like the OLS test, the walk and turn test typically abbreviated as the WAT test is also a divided attention test. While undergoing this test, you have to be mentally and physically alert. There are several alternative names for a walk and turn test, including the DUI straight-line test, the nine-step walk turn, and the DUI walk the line test. There is a high correlation between poor performance in this DUI test and a BAC of .08% or above.

While administering this test, the officers give numerous instructions to a driver. A driver has to follow the instructions issued by the police and, at the same time, perform some physical exercises. The police might instruct you to take nine heel-to-toe steps on a line, either real or imaginary. You may also have to take nine heel-to-toe steps back or pivot around.

As you follow the instructions, the police will be looking out for signs of intoxication. The police will be keen to check whether you can maintain balance and to follow instructions. The police will also check whether you start walking too soon or whether you stop walking. The police will observe whether you step off the line and whether you can carry out the heel-to-toe steps.

If you use your arms to balance or if you fail to make correct turns, it may be a sign of intoxication. If you are under the influence of alcohol, you may not manage to perform physical and mental tasks at the same time.

The Horizontal Gaze Nystagmus Test

Commonly abbreviated as the HGN, horizontal gaze nystagmus refers to the involuntary jerking of the eyes to the side. This movement is involuntary, and if you experience it, you may not be aware of its occurrence. There are several types of nystagmus, and there are several causes of the condition. Some of the eye movements are influenced by alcohol. While administering this test, the officers might instruct you to follow with your eyes a stimulus to the right and the left. As you follow the gaze, the police will be observing the angle at which your pupils start to exhibit. If you have an early onset of nystagmus, typically before a 45-degree angle, it will be a sign of a BAC of .08% or more.

The NHTSA states that the horizontal gaze nystagmus test is effective in determining whether a driver is under the influence of alcohol.

Non-Standardized Field Sobriety Tests

The NHTSA has only standardized three sobriety tests. However, the police might also rely on the non-standardized field sobriety tests to determine whether a driver is under the influence of alcohol. However, in the case of non-standardized sobriety tests, there is little correlation between DUI impairment and the outcome of the tests. The administration of the non-standardized tests may vary greatly from one police officer to the other. Therefore, the legitimacy of the non-standardized tests is often questionable. Some of the common standardized tests that California police use include:

● The hand pat field sobriety test

● The finger to nose test

● Rhomberg balance test

● The Finger Count test

Challenging the Outcome of Field Sobriety Tests

You do not always have to go by the outcome of field sobriety tests. With the help of an experienced La Presa DUI attorney, you can challenge the results obtained from field sobriety tests. An attorney can use several strategies to challenge the reliability of field sobriety tests. For instance, before administering the tests, the police have to make certain conditions suitable. Adverse conditions may make it hard to administer the tests and also affect the outcome of the tests. Some of the factors that your attorney can cite while challenging the results include:

Poor Testing Conditions

Your La Presa DUI attorney may challenge the outcome of the field sobriety tests based on the condition of the surface where the police administered the test. The law requires the police to administer field sobriety tests on a ground, which is hard, dry, non-slippery, and level. The DUI suspect must have ample space to perform and complete the test. If the police failed to adhere to these requirements, your attorney might reject the results of the field sobriety tests.

The police have to ensure that the testing venue has adequate lighting before administering the FSTs. At the time of the testing, you should be able to see the ground below and the testing officer. The police might provide artificial lighting using a flashlight if the lighting is inadequate. If the test is performed in darkness, it may be hard even for a sober person to complete the test.

If poor auditory conditions were present, your attorney might use it as a ground to fight your DUI charges and challenge the credibility of FSTs results. For instance, if the police perform the test amidst the noise, sirens, honking, and other disruptive noises, the outcome of the test may be questionable.

Poor Health and Physical Conditions

Your DUI attorney may also link poor outcomes in field sobriety tests to other conditions, including poor health. One of the leading causes of poor performance in FSTs is old age. If you are above 60 years, you may not perform well in the tests due to balance issues. You may also perform poorly in the tests if you are ill or if you have leg or back problems. If you have hearing issues, you may not be able to follow the directions from the police.

If you are overweight and if you are experiencing pain, you may perform poorly in the field sobriety tests. You may also perform poorly in the tests if you were nervous or feeling intimidated at the time of the test. Drivers with mild or advanced brain damage may perform poorly in field sobriety tests. If you have a mental disability, which makes it hard for you to follow instructions, it might be difficult for you to excel in field sobriety tests. Your attorney may defend you, especially if you suffer from any condition that may make it hard for you to complete the field sobriety tests.

Non-Alcohol Related Cause

Sometimes, you may perform poorly in field sobriety tests due to non-alcohol related causes. The police might interpret your lack of physical coordination to alcohol or drugs, while in the actual sense, you may be suffering from another condition. For instance, you may have poor coordination if you are on medication, which is causing drowsiness. The poor performance in the FSTs may also be due to lack of sleep and due to other factors like dehydration and exhaustion. You may perform poorly in the tests if you are experiencing muscle fatigue due to a workout and also if you are suffering from strained or pulled muscles.

Submitting to Field Sobriety Tests

In California, you cannot face penalties for failing to submit to field sobriety tests. In most cases, DUI attorneys advise drivers that in case a police officer suggests a field sobriety test, you should decline the offer politely. In most cases, FSTs end up in failure and hardly influence the police

's decision to arrest you for DUI. Even if you excel in the field sobriety tests, as long as the police believe that you are under the influence of alcohol, the police will still arrest you. Therefore, instead of submitting to the tests, you may choose to contact your DUI attorney.

Other Ways of Determining Intoxication

Other than administering field sobriety tests, the police might also employ other methods to determine if you were driving a vehicle under the influence. Some of the methods include:

  1. DUI Breath Tests

The DUI breath test is the most common method of measuring blood alcohol content in California. The popularity of this testing method is because it is minimally invasive, and it delivers accurate results. There are two types of DUI tests in California, the Pre-arrest tests, also known as the preliminary alcohol screening (PAS) and the post-arrest DUI test.

A DUI breath test helps to determine the amount of alcohol in your breath. The police might administer a breath test at the side of the road using a breathalyzer machine. The police might administer the PAS test before arresting you at a DUI checkpoint. However, you can decline a PAS test without facing penalties as long as you are not below 21 years, and you are not on probation for committing a prior DUI offense.

The police might also administer the DUI breath test after legally arresting you. If the police recommend this test, you have to submit to the test even if you had previously taken a PAS breath test. If you refuse to submit to this chemical test, you may face adverse consequences, including suspension or revocation of your California driver's license for a minimum of one year.

The post-arrest breath test may be almost similar to a PAS test if the police decide to administer the test at the side of the road. However, the police might also administer the test at the police station on a desktop device. However, it is important to note that unlike a PAS test, a post-arrest test is mandatory irrespective of where it is administered.

Challenging DUI Breath Test Results

Just like in the case of FSTs results, you may challenge the outcome of DUI breath tests with the help of your attorney. For instance, your La Presa DUI attorney may consider the condition of the breathalyzer machine used to conduct the test. The law requires a breathalyzer machine to be well maintained and calibrated to ensure it gives reliable results. If your attorney realizes that the breathalyzer was not in good condition at the time of conducting the test, it may form a good basis for rejecting the results.

The attorney may also consider whether the police follow the correct testing procedures. According to the law, only a qualified person should administer a DUI breath test. If an unqualified person conducts the test, you may question the credibility of the test results.

  1. DUI Blood Tests

In some situations, a DUI blood test may come in handy in determining the level of intoxication in a driver. If you are a licensed driver in California, the law deems that you have consented to a DUI breath test and a DUI blood test. This is according to the implied consent law in California. In most cases, the police will give a driver the choice of undergoing a breath test or a blood test. In some instances, a blood test may be the only option.

If the police suspect that you are under the influence of drugs, they may recommend a blood test. It is not possible to determine the content of drugs in your system using a breath test. A blood test may also be ideal if a driver is unconscious. If you are in a medical facility where a breathalyzer is not available, a DUI blood test may be ideal.

Fighting the Outcome of Blood Test

With the help of your La Presa DUI attorney, you can challenge the reliability of DUI blood test results. For instance, the results of the blood test may not be accurate if the testing person mishandled the blood sample leading to contamination.

Your DUI attorney may file a motion of exclusion of the DUI blood test results from the evidence. The attorney may cite raising blood alcohol as a defense. After you consume alcohol, your body continues to process its components. Therefore, the alcohol content in the blood may not be very high immediately after you finish consuming a drink. Therefore, it may be possible to prove that at the time of driving, the alcohol content in the blood was lower than the allowable limit of .08%. You may point out that your blood alcohol levels rose between the time of your arrest and the time of DUI testing.

Your attorney may also defend you by outlining that the police violated your Fourth Amendment Rights. Before stopping your vehicle, the law requires the police to have probable cause. If the police did not have a valid cause for stopping your vehicle, they might have violated the provisions of the Fourth Amendment. Therefore, your DUI attorney may be able to convince the court to dismiss your case.

You may also cite the mistake of fact as a defense for a DUI charge in California. For instance, you may have made a mistake while ingesting prescription medication. However, for your attorney to use this defense, you must have made an honest mistake. You may not have been aware of the adverse effects of a prescription medication leading to adverse effects.

Find a La Presa DUI Lawyer Near Me

The penalties of driving a vehicle under the influence of alcohol or drugs in California may be detrimental. It is advisable to have an experienced DUI attorney to fight your DUI charges. San Diego DUI Attorney can assist you in fighting DUI charges. Contact us at 619-535-7150 and talk to one of our attorneys.