California Vehicle Code 23152(a) prohibits driving under the influence of alcohol. This means you could be convicted even if your BAC is below 0.08% because the only factor is whether you are too intoxicated to operate a vehicle safely.
DUI is typically charged as a misdemeanor crime unless aggravating circumstances exist. A DUI conviction carries substantial fines, probation, license suspension, mandatory DUI classes, and the possibility of jail time, underscoring the serious consequences of driving under the influence.

Suppose your breath or blood test shows a BAC of 0.08% or higher. In that case, you will face charges of both VC 23152(a) VC drunk driving and VC 23152(b) driving with a BAC of at least 0.08% (DUI per se).
VC 23152(a) states, "It is unlawful for a person who is under the influence of any alcoholic beverage to drive a vehicle. (b) It is unlawful for a person who has 0.08 percent or more, by weight, of alcohol in their blood to drive a vehicle," highlighting the strictness of the law and the need for caution and compliance.
The closely related law, California Vehicle Code 23152(b) VC makes it automatically (per se) illegal to drive a motor vehicle with a BAC at or above 0.08%. The term 'per se' means that the law automatically considers you guilty of a crime if certain conditions are met, in this case, having a BAC at or above 0.08%.
As noted, DUI is typically a misdemeanor, and the penalties grow more severe with each conviction. Simply put, Vehicle Code 23152(a) makes it illegal to operate a vehicle while under the influence of alcohol or drugs. The term "under the influence" means having impaired physical or mental abilities to the extent that you cannot exercise the caution typical of a sober person under similar circumstances.
Notably, this law applies regardless of your BAC level, meaning police can arrest you for DUI solely based on whether you display common signs of impairment, such as erratic driving, slurred speech, or failing field sobriety tests.
In other words, this law applies when your physical or mental abilities are impaired to the extent that you can no longer drive as safely as a cautious, sober person.
After all DUI arrests in California, you must submit to a breathalyzer or blood test to measure your blood alcohol content (BAC). As noted, you can be convicted of DUI alcohol even if the alcohol test results are within the legal limit of less than 0.08%.
What is Circumstantial Evidence in a DUI?
Prosecutors usually depend on circumstantial evidence to show that you were driving impaired by alcohol. Typically, police officers will note in their arrest report that they observed you doing the following:
- Swerving or driving erratically.
- Smelling of alcohol.
- Had slurred speech.
- Had glassy, watery, or bloodshot eyes.
- Walked unsteadily with an uneven gate.
- Admitted to drinking.
- Failed the PAS test and field sobriety tests.
California prosecutors must prove beyond a reasonable doubt that you drove a motor vehicle and that you were under the influence of alcohol at the time you drove.
As noted, as a DUI suspect, you will typically face charges for not only drunk driving under 23152(a) VC but also DUI per se under 23152(b) VC, making driving under the influence a crime even if your BAC is legal.
When Is DUI a Felony in California?
Most DUI offenses in California are misdemeanors, but prosecutors may escalate your charge to a DUI felony offense if any of the following are true:
- It is your fourth DUI (or wet reckless) offense within 10 years.
- You have a prior felony DUI conviction, or
- Anyone was injured or killed as a result of the incident.
Felony DUI may result in significantly higher fines and prison time if you are convicted.
What are the Penalties for a Misdemeanor DUI?
A misdemeanor DUI conviction means you will face a range of penalties, which could escalate depending on aggravating factors, such as a refusal to submit to a chemical test or a particularly high BAC level. However, typical penalties for a first, second, or third offense, penalties include the following:
- Probation: Informal probation lasting three to five years.
- Jail Time: A first offense can result in up to six months in county jail, while subsequent offenses can result in up to a year in jail.
- Fines and Fees: You might face fines and court-related fees.
- Alcohol Programs: Mandatory enrollment and completion of alcohol and drug education classes are common requirements.
- Driver's License Suspension: The Department of Motor Vehicles (DMV) is responsible for suspending or restricting your driving privileges for at least 6 months on a first offense, with longer suspensions for subsequent offenses. The DMV also conducts administrative hearings to determine the validity of the suspension or revocation of your driver's license.
- Installation of an Ignition Interlock Device (IID): Courts might order IID installation, especially for repeat offenses. An IID is a breathalyzer for your car that prevents the vehicle from starting unless you provide a clean breath test. You must blow into the device before starting the car, and if alcohol is detected, the car won't start.
What are the Aggravating Factors?
Some factors can enhance the DUI penalties for a misdemeanor DUI conviction, such as the following:
- Excessive BAC levels (0.15% or higher).
- Endangerment of minors (having minors under 14 in the vehicle).
- Reckless driving, such as excessive speeding.
- Refusal to submit to chemical testing.
Each of these factors can intensify sentencing, leading to additional financial penalties or extended jail time.
What are the Common Defenses?
When facing misdemeanor DUI charges, defendants might have several viable defenses. A California criminal defense attorney will evaluate the circumstances of your case to develop a defense strategy most suitable to your situation. Common defenses include:
- Lack of Probable Cause: Police must have a valid reason to stop your vehicle. If the stop was made without probable cause for a traffic violation, the evidence gathered after the stop could be suppressed.
- Procedural Errors: Arresting police officers must adhere to legal protocols during a DUI investigation and arrest. Mistakes like improper breath test administration or failure to advise the suspect of their rights can weaken the prosecution's case.
- Challenging Chemical Testing Results: Breathalyzer and blood tests can be challenged due to faulty equipment calibration or improper handling of evidence.
- You Were Not Impaired: Signs of perceived impairment might have alternative explanations, such as fatigue, illness, or anxiety. This defense often requires expert testimony to dispute officer observations.
For more information, contact our Los Angeles DUI lawyers, Cron, Israels & Stark.
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