When being investigated for driving under the influence of drugs or alcohol, it may be reasonable to hope that the prosecutors won’t find substantial evidence to charge you. Vista DUI Attorney Law Firm can help you understand your rights throughout the investigation process and increase the chances of having the charges dropped/reduced. Our lawyers, who serve clients across Vista and North County, California, have expertise in DUI and DMV related cases. Here’s what you should know about the investigation process for DUI offenses.

Investigations for DUI Cases in California

The US Constitution mandates law enforcement officers to have a certain justification level before initiating a traffic stop or arrest. For a DUI offense, they must have reasonable suspicion that you drove your car while intoxicated with drugs or alcohol. They should also have a probable cause for initiating the arrest.

Prior to a DUI investigation, you must have been pulled over or stopped by the California Highway Patrol or police officer for driving under the influence of drugs or alcohol. Since the 4th Amendment to the US Constitution forbids unreasonable seizures and searches, the officer has no mandate to pull you over for no reason. The officer must state the facts that made you a suspect to a DUI offense.

A simple traffic violation or infraction may help the law enforcement officer open a DUI investigation against you. Before the process begins, the officer must articulate reasons for stopping your car and other reasonable suspicions. Facts to back up a reasonable doubt in a DUI case include the driver evading a stop sign or the vehicle emerging from an area known for having a large number of alcohol bars.

Other facts that give a probable cause for the officer to arrest and investigate you are as follows:

  • Having watery or red eyes and a flushed face among other physical symptoms exhibited by intoxicated drivers
  • Producing a smell of alcohol or an alcoholic beverage from your breath
  • Having an open alcohol container in your vehicle

The DUI investigation commences once a law enforcement officer believes that you're guilty of driving under the influence. Expect the investigation to involve questions about whether, where and the amount of alcohol you've been drinking. The process may also include field sobriety tests (FSTs) and a preliminary alcohol screening test (PAS test) administered using a handheld breathalyzer.

Field Sobriety Tests in DUI Investigations

FSTs are a series of mental and physical exercises administered by the police officers to help support a DUI investigation. Scoring poorly in FSTs may imply that you're intoxicated by either alcohol or drugs or a combination of both. Law enforcement officers rely on your FST results to decide whether or not to arrest you.

Types of Field Sobriety Tests Administered in California

According to the NHTSA (the National Highway Traffic Safety Administration) instructor manual, FSTs can either be standardized or non-standardized. Standardized ones have been approved by the NHTSA while the standardized ones haven't. Regardless of their approval, law enforcement officers use the tests to gauge your level of impairment.

A typical example of a standardized FST is the one-leg stand test, which involves raising your foot up to six inches off the ground while holding still in that position. As you perform this test, expect the officer to observe the way you're swaying, using your arms to balance, hopping and putting your foot down. Other types of standardized FSTs include the Horizontal Gaze Nystagmus and the Walk and Turn test.

Nonstandardized FSTs are rarely used because they demonstrate little or no correlation between mental/physical ability and DUI impairment. An example of a non-standardized FST is the hand pat test, which involves patting one side of your hand and then the other side as you count. The officer will observe your ability to count correctly, your ability to adhere to the instructions, the sequence, and rotation of the patting, and proper timing of when you start and stop the test. Other forms of non-standardized FSTs include the finger-to-nose test, the finger count and the Romberg balance test.

Are Field Sobriety Tests Mandatory?

Since FSTs are optional in California, you can decline to have them administered without facing any punishments whatsoever. One of the reasons behind them being optional is that sober drivers can fail them too. You may be wrongly charged for a DUI offense for failing FSTs while you were sober.

Adverse environmental conditions may make FSTs hard to perform. The NHTSA recommends law enforcement officers to administer FSTs under safe and appropriate test conditions. California juries and courts usually expect that FSTs were given under reasonable and fair conditions.

Surface conditions for administering FSTs include dry, hard, level and non-slippery surfaces with sufficient room for you to complete or perform the test. The auditory ones include your ability to hear the police officer giving you instructions during the FSTs. As far as the lighting conditions are concerned, FSTs should be provided in an environment with sufficient lighting. You (the suspect) must be able to see the ground below and the officer well.

Preliminary Alcohol Screening Tests in DUI Investigations

Amid a DUI investigation in California, a police officer may administer you two separate tests establishing your BAC (blood alcohol level). The tests include a preliminary (pre-arrest) alcohol screening breath test and a post-arrest breath test or blood test. Unlike a post-arrest breath/blood test, a PAS test is usually optional unless you're on probation for a prior DUI conviction or you're below 21 years of age.

PAS tests are administered using a breathalyzer before going to the police station while post-arrest breath tests are administered through a desktop controlled device at the station. After being arrested, you can't refuse to take a breath test unless you provided a blood test or asked to take a blood test. Pursuant to Vehicle Code 23136, drivers under 21 years of age must take a PAS test or risk having more than a one-year license suspension. Vehicle Code 23154(a), on the other hand, mandates people with prior DUI convictions to submit to a PAS test if they drive with any BAC in their system.

How Do PAS Tests Work?

Once alcohol is absorbed in your stomach and small intestine, it usually flows into the blood and carried to your organs. During the time you're intoxicated, a small alcohol amount will be excreted into your lungs making it easy to measure your level of impairment using breath testing devices. Since breath testing devices don't measure BAC directly, they convert your breath alcohol content to a BAC estimate. Along these lines, breath tests are less reliable than blood tests in DUI investigations.

Blood Tests Vs. Breath Tests

Unlike breath test, blood tests measure the alcohol amount in your blood, giving the most accurate BAC results. When this test is being administered, expect a state-licensed expert to take your blood sample and send the sample to a local laboratory for further analysis. Breath test results appear in a shorter time while blood test results take several days. However, the blood samples can be saved and used by you to challenge wrongful prosecution.

Though urine tests can detect the presence of alcohol in your system, they are less reliable than breath tests and blood tests. A urine test will only be administered in a DUI case in California if both a breath test and blood test are unavailable. The test may also be administered if you have a medical condition (such as a clotting disorder or breathing disorder) or an extremely high unconsciousness level that makes you incapable of completing a breath test.

Which Offenses Can Result in You Being Under Investigation for a DUI in California?

Common DUI offenses in California include driving under the influence, driving with a 0.08% BAC or higher, and underage driving with a 0.05% BAC or higher. Others include driving under drug influence and commercial driver DUI. Committing such crimes may make you a subject to a DUI investigation as discussed below.

  1. Driving Under Alcohol Influence

Pursuant to Vehicle Code 23152(a), it's unlawful to drive any motor vehicle with alcohol in your system. Being under alcohol influence can impair your mental or physical abilities making you incapable of operating a motor vehicle. The DUI investigation will involve a prosecution team, constituting of a prosecutor, arresting officer or expert witness (who's usually a forensic toxicologist working for a law enforcement agency).

The prosecution team will begin the investigation by proving that you didn't have the physical or mental ability to operate your car safely. In this process, the arresting officer may testify that you drove erratically, swerved/weaved or were unable to drive soberly. The officer can base the testimony on the fact that you had slurred speech, red and watery eyes, wobbliness on your feet or an alcohol odor in your breath.

  1. Driving with a 0.08% BAC or Greater

Operating a motor vehicle with a 0.08% BAC or higher is a crime under California’s Per Se DUI Law (VC 23152(b)). The DUI investigation for this offense will be based on various elements, which include the fact that you drove a car and the fact that you had a 0.08% BAC or greater when driving a car. To prove that you drove the car, the traffic officer who stopped you for drunk driving will testify. A chemical breath or blood test that was taken within three hours of being stopped by the police can help prove your BAC (blood alcohol content).

  1. Underage Driving with a 0.05% BAC or Greater

Though it’s considered as an infraction (a minor crime), driving with a 0.05% BAC or higher is a violation of Vehicle Code 23140. In this case, you must be below 21 years of age and be found guilty of having a 0.05% BAC or higher at the time of the traffic stop. A standard breath or blood test will be used to measure your blood alcohol level and determine whether you violated VC 23140.

  1. Driving Under the Influence of Drugs

Driving with drugs in your system is a violation of VC 23152(f) provided that the drug is a prescription, an illegal or an over-the-counter drug. You’ll also be charged for this violation if you had a combination of alcohol and any drug at the time you were driving. The investigation process of this offense begins with the arresting officer testifying that you drove in an unsafe manner. The officer may also present your performance on field sobriety tests and a breath test or state the physical symptoms of intoxication that you exhibited.

A drug recognition expert can be brought in as an expert witness pursuant to Vehicle Codes 23152(f) and 23152(g). The DRE may confirm that your impairment was caused by drugs and conclude that your system had one or more types of drugs. Examples of these drugs include marijuana, hallucinogens (mushrooms or LSD), narcotic analgesic (heroin or codeine) and central nervous stimulants/depressants. Without the DRE’s testimony, your attorney may argue for charge reduction or dismissal.

  1. Commercial Driver DUI

You’ll be charged under VC 23152(d) for operating a commercial vehicle with a 0.04% BAC or higher. For a vehicle to qualify as a commercial vehicle in California, you must have a Class B license or a Class C license (a standard license with a commercial endorsement). Smaller commercial vehicles include tank vehicles, school buses, farm vehicles, double trailers and passenger vehicles carrying over ten people. Large commercial vehicles may include 3-axle vehicles that weigh more than 6,000 pounds and vehicles with a marked GVWR (Gross Vehicle Weight Rating) of over 26,000 pounds.

Once the prosecution team proves that your vehicle meets the commercial vehicle criteria, you’ll be cited for driving under alcohol influence. In this case, the investigation will entail proving that you were over the legal alcohol limit (0.04$ BAC or higher) while operating the vehicle. Breath/blood tests and testimony from the arresting officer help build your case.

Which DUI Defense Strategies May Help When You’re Under a DUI Investigation?

Regardless of the facts or pieces of evidence used by the prosecutors to build a DUI investigation, there's always various defense strategies to use. If these defenses work, your lawyer stands a chance to persuade the prosecution team to agree to a charge dismissal or reduction. The arguments are as follows:

  1. Filing a Motion to Suppress the Obtained Evidence

Pursuant to Penal Code 1538.5, a California court can suppress evidence obtained through a search warrant that was deficient or issued without a probable cause. The court may also suppress the evidence if it was obtained without a search warrant. Your lawyer needs to file a motion to suppress evidence before the actual criminal trial begins whether you're facing a California felony or misdemeanor DUI. Expect the motion to be addressed at the pretrial hearing meant or at the preliminary hearing.

  1. Attributing the Poor Performance in FSTs to Physical and Mental Conditions

Besides intoxication, mental and physical conditions can make you (a sober motorist) perform poorly on a field sobriety test. Common mental/physical causes of the poor performance include being over 60 years of age, being ill/sick, having a leg, foot, or back problems or having inner ear problems. Being overweight by 50 pounds or more, being in pain, being nervous or intimidated and having mild brain damage may also hinder your performance in the test.

  1. The FSTs Were Administered in an Unsuitable Environment with Improper Timing

The NHTSA advises law enforcement officers to administer FSTs in suitable environmental conditions with the proper timing. Results of an FST may be inaccurate if the officer incorrectly starts or ends the time or fails to time the test using a watch. You may also allude that poor lighting, inclement weather and uneven roads or surfaces lead to your poor FST performance.

  1. Causes for Lack of Coordinated Driving Were Non-alcohol Related

Lack of coordination when operating a motor vehicle may make a police officer assume that you're intoxicated with drugs or alcohol. Such an impairment may be caused by medication (such as medicine is taken to control seizures), lack of sleep, dehydration, exhaustion or muscle fatigue from a heavy workout routine. Instead of facing DUI charges, you may be charged with a traffic infraction (which is less severe) if you test negative for drugs or alcohol.

  1. The DUI Sobriety Checkpoint Wasn’t Set Up in Compliance with the California Laws

DUI sobriety checkpoints in California must adhere to specific legal requirements. The requirements include publicly advertising a DUI roadblock and ensuring that the field officers are following a predetermined formula for stopping cars. Others include having supervising officers oversee and organize the checkpoint. Your lawyer could challenge your arrest and fight the DUI charges if one or more of these requirements weren't met.

Seek Legal Help When Under a DUI Investigation From a Competent Lawyer Near Me

Though law enforcement officers tend to be thorough with DUI investigations, enlisting a lawyer's help can help you fight for your innocence by challenging their findings. Our goal at Vista DUI Attorney is to use suitable legal defense strategies in your favor to guarantee you less severe outcomes. As we operate in Vista and North County, CA, we're well versed with DUI and DMV related cases including driving under the influence, license suspension, DMV hearings, and DUI hit and run among others. Call 760-691-1540 to arrange an initial consultation meeting with one of our DUI defense lawyers.