California DUI Laws: Vehicle Code §23152(a) and §23152(b)

A charge for Driving Under the Influence (DUI) under California Vehicle Code §§23152(a) and 23152(b) is one of the most common—and most serious—criminal cases in California. A conviction can mean jail time, loss of your driver’s license, high fines, mandatory classes, and a permanent record.

At Radford & Rome, LLP, we’ve seen both sides of these cases. As former prosecutors, we know exactly what the government focuses on, how they prove DUIs, and how to fight back effectively.

Understanding California Vehicle Code §23152(a)

Under Vehicle Code §23152(a), it is illegal to drive “under the influence of alcohol.”
This charge does not depend on your blood alcohol concentration (BAC). Instead, prosecutors must prove that your mental or physical abilities were impaired to the extent that you could no longer drive as a sober, cautious person would.

They typically rely on:

  • Police officer observations (speech, coordination, red eyes, odor of alcohol)
  • Field Sobriety Test (FST) performance
  • Your statements at the scene
  • Video or body-cam evidence

Even with a BAC below 0.08%, you can be convicted under §23152(a) if the prosecution convinces a jury that your driving was impaired.

Understanding California Vehicle Code §23152(b)

Under Vehicle Code §23152(b), it is unlawful to drive with a BAC of 0.08% or higher.
This is a “per se” DUI, meaning the law presumes impairment once your BAC meets that threshold—regardless of how well you were driving.

Evidence commonly used includes:

  • Results from a breath or blood test
  • Chain of custody records for blood samples
  • Calibration and maintenance logs for breath-testing devices

What Prosecutors Focus On Most

In almost every DUI prosecution, the same three factors determine how aggressively the case will be pursued and whether it can be reduced or dismissed:

  1. Driving Pattern:
    The most critical element. Prosecutors look for weaving, speeding, drifting, abrupt stops, or traffic violations captured by dashcam, witnesses, or 911 calls. If your driving pattern appears normal, the state’s case weakens significantly.
  2. Collision Evidence:
    Any accident—especially if another vehicle or property was involved—dramatically increases the perceived danger and likelihood of filing harsher charges such as VC 23153 (DUI with injury). Even minor fender-benders are used to argue recklessness or impairment.
  3. Blood Alcohol Concentration (BAC):
    The higher your BAC, the stronger the presumption of impairment. Prosecutors use breath or blood test results to argue both per se violation under §23152(b) and general impairment under §23152(a).

A skilled DUI attorney challenges all three. We can contest the traffic stop, question the accident reconstruction, and scrutinize the chemical testing procedures for accuracy and legal compliance.

Field Sobriety Tests (FSTs): What You Should Know

Field Sobriety Tests (FSTs) are not mandatory in California. Officers may ask you to perform balance or coordination tests like the walk-and-turn, one-leg stand, or horizontal gaze nystagmus (HGN) test.

These tests are highly subjective and often unfairly administered:

  • They don’t account for fatigue, medical issues, or uneven surfaces.
  • Officers rarely follow the exact standardized instructions required under NHTSA guidelines.
  • Their scoring is biased toward confirming impairment rather than measuring it.

Refusing FSTs cannot be used against you in the same way as refusing a chemical test, but performing them can give police evidence to justify your arrest.

Chemical Testing and Refusals

Once arrested for DUI, California’s implied consent law requires you to submit to either a breath or blood test. This is separate from the roadside PAS (Preliminary Alcohol Screening) test.

If you refuse to take a post-arrest chemical test:

  • The DMV will impose a mandatory one-year license suspension for a first refusal.
  • You will be ineligible for a restricted license during that period.
  • The prosecutor can add a “refusal enhancement” to your case, which carries additional jail time if convicted.

Even if you refuse, law enforcement can and often will obtain a search warrant to draw your blood forcibly. Refusal does not stop them from getting your BAC—it only adds penalties.

How the DMV Suspension Works

Immediately after your arrest, the officer will take your license and issue a temporary one valid for 30 days.
You have 10 days to request a DMV Administrative Per Se (APS) hearing to challenge the automatic suspension.

If you don’t request the hearing in time, the DMV will suspend your license even before your criminal case begins.
Winning the APS hearing can set aside the suspension, but if you’re later convicted in court, a separate suspension may still apply.

Our firm handles both the DMV and court sides of DUI defense to ensure the best strategic outcome.

Possible Plea Reductions: Wet Reckless and Dry Reckless

Even when a DUI cannot be dismissed outright, it’s often possible to negotiate a plea to a lesser offense that carries lighter penalties and fewer long-term consequences.

Wet Reckless (Vehicle Code §23103.5)

A “Wet Reckless” is essentially a reckless driving conviction involving alcohol, but it is not a DUI.
It carries no mandatory license suspension and usually no jail time.
However, it counts as a prior DUI if you are arrested again within ten years.

Dry Reckless (Vehicle Code §23103)

A “Dry Reckless” is a reckless driving conviction without any reference to alcohol.
It does not count as a prior DUI and is treated like a standard misdemeanor traffic offense.
It’s often the ideal resolution in borderline or low-BAC cases where evidence is weak.

At Radford & Rome, LLP, our attorneys routinely negotiate these outcomes when it’s in the client’s best interest, saving clients from the financial, professional, and personal impact of a full DUI conviction.

Penalties for DUI Under 23152(a) or (b)

Penalties vary depending on your record, but for a first-time misdemeanor DUI, you can expect:

  • Up to 6 months in county jail
  • Fines and assessments totaling $2,000 or more
  • DUI education program (3–9 months)
  • 4-month license suspension (or 6–10 months if combined with court action)
  • Ignition Interlock Device (IID) installation for up to 6 months
  • 3 years of probation

Repeat offenses, injury DUIs, or refusal cases carry far harsher penalties—including mandatory jail time and multi-year license suspensions.

Building a Strong DUI Defense

An effective DUI defense begins by examining every element of the case:

  • Was the traffic stop lawful?
  • Were your rights read correctly?
  • Were FSTs or breath tests conducted according to regulations?
  • Were your BAC results scientifically reliable?

We often employ experts in toxicology, forensic analysis, and accident reconstruction to challenge the prosecution’s assumptions and restore balance to the case.

Why Hire Radford & Rome, LLP?

At Radford & Rome, LLP, every attorney on your case is a former prosecutor with extensive experience in DUI law and DMV hearings across Southern California. We know how police reports are written, how prosecutors evaluate evidence, and how judges view DUI cases—and we use that insight to your advantage. If you’ve been arrested under Vehicle Code §23152(a) or §23152(b), don’t wait.

You only have 10 days to protect your license. Call Radford & Rome, LLP today for a free consultation. We represent clients throughout Los Angeles, Riverside, San Bernardino, Orange, and Ventura Counties and are available 24/7 to start building your defense.