Facing DUI charges in California—especially in areas like San Diego—can be overwhelming. But not all evidence collected during a DUI investigation is automatically valid or admissible in court.
Challenging the prosecution’s evidence can lead to reduced charges—or even dismissal of your case. Below, we break down five powerful legal strategies used by defense attorneys at Carolyn L. Oliver | Criminal Defense Law Firm to suppress evidence and protect your constitutional rights in DUI cases.
Motion to Dismiss Under California Penal Code § 995 (Felony DUI)
When you’re facing felony DUI charges, one early option is to file a Penal Code § 995 motion to dismiss. This motion challenges whether there was sufficient probable cause for the charges during your preliminary hearing.
If the court agrees that the evidence doesn’t support one or more charges, the judge can reduce or dismiss those charges entirely.
At Carolyn L. Oliver | Criminal Defense Law Firm, we carefully analyze your case file to determine if a 995 motion could be a strong first step in weakening the prosecution’s case.
Motion to Suppress Evidence (Penal Code § 1538.5)
A motion to suppress evidence challenges any evidence obtained in violation of your constitutional rights, including the Fourth Amendment (unlawful searches or stops) and the Fifth Amendment (statements made without proper Miranda warnings).
These motions can apply to:
- Unlawful traffic stops
- Improperly conducted field sobriety tests
- Unreliable breath or blood test results
- Statements made without Miranda advisement
If granted, this motion can eliminate critical evidence—potentially dismantling the State’s case.
Suppressing the Initial Traffic Stop (Fourth Amendment Violations)
Every DUI case begins with a stop—but that stop must be lawful.
If the officer did not have reasonable suspicion or probable cause (such as a traffic violation or observable impairment), any evidence collected after the stop may be considered inadmissible.
A Fourth Amendment challenge may be filed to argue the stop violated your rights. If successful, everything that followed—including test results and statements—could be suppressed. This often leads prosecutors to drop or reduce charges.
Challenging Field Sobriety or Chemical Test Results
Field Sobriety Tests (FSTs)
Standardized field sobriety tests (e.g., walk-and-turn, one-leg stand, horizontal gaze nystagmus) must be conducted according to NHTSA protocols. If the officer deviated from proper procedures or conducted the test in inappropriate conditions (like uneven pavement), the results may be unreliable and inadmissible.
Breath and Blood Tests
Breath and blood test results can also be challenged due to:
- Improper administration
- Uncalibrated or faulty equipment
- Violation of the required 15-minute observation period
- Rising BAC defense – arguing your BAC rose after driving but before the test was administered
Our legal team investigates these issues thoroughly to determine whether test results can be challenged or suppressed.
Motion to Suppress Statements Made Without Miranda Warnings
After a DUI arrest, police must read your Miranda rights before custodial questioning. If they fail to do so—or if they continue questioning after you invoke your right to remain silent or request an attorney—any statements you make may be suppressed.
Statements obtained unlawfully can have a serious impact on the case. Our attorneys regularly file Fifth and Sixth Amendment suppression motions to exclude improper statements and protect your rights.
Why You Need a DUI Defense Strategy That Works
Every DUI case is unique. That’s why our attorneys at Carolyn L. Oliver | Criminal Defense Law Firm tailor a custom strategy based on the facts, the officer’s conduct, and how the evidence was obtained.
Our comprehensive approach may include:
- Filing pretrial motions (such as PC § 995 and § 1538.5)
- Challenging test reliability
- Excluding unlawful statements
- Negotiating for reduced charges or diversion programs
When your future is on the line, you need an advocate who knows how to fight smart.
Take Action Today — Protect Your Rights
If you or someone you love is facing DUI charges in California, don’t wait. Early legal intervention can significantly improve your outcome.
Contact Carolyn L. Oliver | Criminal Defense Law Firm today to schedule a confidential case review. Let’s evaluate your options, challenge the evidence, and work toward protecting your freedom and your future.
📞 Call now to schedule your consultation at (858) 456-3572
📍 Serving San Diego and surrounding California communities.
Disclaimer: This article is for informational and marketing purposes only and does not constitute legal advice. Viewing or using this content does not establish an attorney-client relationship. Past results are not a guarantee of future outcomes.
