DUI Laws in California — VC §23152 Explained

The Fourth Amendment requires law enforcement to have reasonable suspicion of a traffic violation or criminal activity before stopping a vehicle. If the initial stop was unlawful, all evidence obtained after the stop — including field sobriety tests, breathalyzer results, and officer observations — can be suppressed under the exclusionary rule. We review dashcam footage, police reports, and witness statements to identify illegal stops.

Breathalyzer devices must be properly calibrated, maintained, and operated by a trained officer. We obtain maintenance logs and calibration records for the specific device used in your arrest. Rising BAC defense: if your BAC was rising at the time of the test but was below 0.08% while actually driving, you may not have violated VC §23152(b) even if the test showed above 0.08%.

Field sobriety tests (FSTs) — walk and turn, one-leg stand, horizontal gaze nystagmus — are notoriously unreliable. Medical conditions, fatigue, anxiety, inner ear problems, uneven surfaces, poor lighting, and improper officer administration can all cause a sober person to fail. We challenge the conditions and administration of every field sobriety test.

Breathalyzers measure alcohol in deep lung air but can be contaminated by residual mouth alcohol from burping, belching, acid reflux, or dental work. California law requires a 15-minute observation period before a breath test to prevent mouth alcohol contamination. Failure to comply with this requirement can invalidate the breathalyzer result entirely.

Several medical conditions can mimic intoxication or produce false BAC results. Diabetes and hypoglycemia can produce ketones that convert to isopropyl alcohol, creating false breathalyzer readings. GERD and acid reflux can cause mouth alcohol contamination. Neurological conditions can cause balance and coordination problems that appear as DUI symptoms on field sobriety tests.

In many DUI cases — especially first offenses with borderline BAC, no accident, and no prior record — we negotiate a reduction of the DUI charge to a 'wet reckless' under VC §23103/23103.5. A wet reckless carries lower fines, shorter DUI school, no mandatory license suspension, and significantly less impact on insurance and professional licenses than a DUI conviction.

The most powerful DUI defense often happens before charges are formally filed. During the prefile window — between arrest and arraignment — we contact the DA's office directly to present mitigating evidence, challenge the strength of the case, and advocate for reduced charges or case rejection. Many DUI cases are resolved more favorably during prefile intervention than after formal charges are filed.