California’s DUI laws can be complex and confusing. In this section, our attorneys break down the rules and explain the process.
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Defendants facing criminal charges for driving under the influence of drugs or alcohol can file a suppression motion asking the court to disregard (“suppress“) all the evidence that law enforcement officers may have unlawfully obtained. If the judge grants this motion, then the prosecution may be forced to dismiss the DUI charges for lack of proof.
Ten typical types of evidence in drunk driving or drugged driving cases include the following:
Note that results of the preliminary alcohol screening test – a roadside breathalyzer test administered to a DUI suspect prior to any arrest – are typically not admissible in DUI criminal trials. Their purpose is merely to help the police determine whether there is probable cause that the suspect has committed driving under the influence of alcohol.
The primary reason that courts throw out evidence in DUI cases is that it was found through an unconstitutional police search and seizure.2 Five examples of such police misconduct include:
Note that courts may suppress illegally-obtained evidence in a criminal case even if the evidence is otherwise relevant and suggests that the defendant is guilty, such as a BAC result that is above the legal limit. Whether the evidence is seized lawfully is more important than what it proves in a DUI case.
While the DUI case is still in the pretrial stage, the defendant (or the defendant’s DUI attorney) files a motion to suppress evidence outlining all the legal reasons why the court should disregard certain evidence. Then the prosecutors will respond, outlining all the legal reasons why the court should admit the evidence. Then the defendant (or DUI defense lawyer) may rebut this response.
Eventually, the court may hold a suppression hearing. Both the defense and prosecution can present their arguments to the judge in open court, and the judge can ask questions of each side. In some cases, the judge decides on the bench whether to grant the motion. In other cases, the judge may take more time to think about it and issue a decision later on.
If the defendant loses the suppression motion, he/she may be able to appeal the decision to a higher court.
California law requires courts to grant suppression motions when the evidence was obtained:
Defendants must prove their motion by a preponderance of the evidence. This means that it is more likely than not that the evidence was unlawfully-obtained and is therefore inadmissible at trial.5
Contact our law firm for a free consultation with our criminal defense attorneys. Our law offices create attorney-client relationships in Los Angeles and throughout California.
A former Los Angeles prosecutor, attorney Neil Shouse graduated with honors from UC Berkeley and Harvard Law School (and completed additional graduate studies at MIT). He has been featured on CNN, Good Morning America, Dr Phil, The Today Show and Court TV. Mr Shouse has been recognized by the National Trial Lawyers as one of the Top 100 Criminal and Top 100 Civil Attorneys.