San Francisco DUI Lawyer California DMV Hearing Attorney

• Introduction
• What To Do First
• Elements of the Offense
• BAC Calculator
• Misdemeanor DUI Case
  • Investigative Considerations
  • Miranda Warnings
  • Pretrial Motions:
    • Suppress DUI Evidence
    • Motion for Discovery
    • Pitchess Motions
    • Blood Sample Motion
    • Motion to Strike Prior
    • Miranda Violations
  • Plea Bargains
• Criminal Jury Trial
• Criminal Court Punishment
• Alternative Sentencing
• Sentencing Enhancements
• Refusal Cases
• Felony DUI Case
• Medication Cases
• Drug Cases
• Federal DUI Case
• Out-of-State Drivers
• Drowsy Driving
• Post-Conviction Relief
• Ignition Interlock Devices
• Motorcycles, Boats, Planes
• California Highway Patrol
• California DUI Resources

Suppress DUI Evidence

A motion to suppress evidence is a legal proceeding designed to challenge evidence on constitutional grounds. Actually, it is a “proceeding within a proceeding” that is brought by a defense counsel in a California criminal DUI case after the initial accusation or indictment has been brought.

Defense attorney initiates the motion to suppress evidence by filing formal papers with the court. The prosecutor and defense counsel then submit legal arguments in an official document known as a brief. If there has been an arrest, then the prosecutor files the first brief. In the prosecutor’s brief, he or she must justify each step taken by the police officer.

The defense attorney then responds with a legal brief explaining how and why the police violated the defendant’s constitutional rights.

A suppression motion in a California DUI case typically challenges the results of the chemical tests administered to determine blood alcohol content (BAC), questions whether police officer had probable cause to make a traffic stop and arrest, or both.

Motion to suppress based on whether or not police had probable cause to make a traffic stop usually focus on whether or not the officer had a reasonable belief that a crime was being committed. If the motion is successful, statements obtained as the result of an unlawful arrest or search will be suppressed.

Any California Vehicle Code violation can establish probable cause for a traffic stop; however, in most cases, the violation must occur in the officer's presence. Police cannot stop a car just to determine whether the driver has a valid driver's license and registration.

It is also unlawful to stop a vehicle in anticipation of discovering a vehicle code violation or other contraband, such as drugs, when no actual probable cause has presented itself to the officer before the stop.

Motions to suppress chemical test results generally center on whether the test was conducted properly. If any of the strict guidelines surrounding chemical test administration were not followed, the evidence probably will be suppressed. If the motion is successful, evidence gained as a result of the test also would be suppressed, such as observations of signs and symptoms of intoxication. A motion to suppress can be brought on several different grounds.

California drivers accused of DUI fear that chemical test results and other evidence means an automatic conviction, but that's not the case. Prosecution evidence is not automatically admissible - it must meet strict legal requirements to be used at trial. A California criminal defense attorney who concentrates on DUI defense will challenge the admissibility of evidence to improve a driver's prospects at trial.

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