What Kind of Evidence Is Inadmissible in Court for a DUI Case in California?
Getting charged in California for a DUI can greatly impact your life. California has harsh punishments for drivers found to be driving under the influence of drugs or alcohol. You could face jail time, a long license suspension, and thousands of dollars’ worth of fines. This is true whether you’ve been convicted of a DUI offense before or if you have a clean criminal record.
Your best defense against a DUI charge may come from understanding the kind of evidence that is inadmissible in court. Consulting with an experienced our DUI lawyer is a great first step to contesting a DUI offense. You can schedule a free consultation today by filling out the form on this page, or by calling us directly at
The California Evidence Code defines what kinds of evidence are admissible or inadmissible for all court cases in the state. Like all criminal charges, the evidence provided to the court in a DUI case must have two general factors:
Reliability refers to evidence that is consistent with known facts. Frequently, "Eyewitness Testimony" can be challenged for reliability. However, a skilled DUI lawyer may also challenge certain pieces of physical or chemical evidence if there is a reason to doubt its reliability.
All evidence must also be relevant to the criminal charge at hand. Evidence that does not serve to prove or disprove a fact that is related to the charge is inadmissible in court. Unfortunately, it’s not always perfectly clear whether a piece of evidence will be considered relevant to a criminal charge. If you think you’re likely to encounter evidence in court that isn’t relevant, a DUI lawyer can help have it stricken as inadmissible.
Kinds of Inadmissible Evidence:
While the law states that evidence is admissible only when it is reliable and relevant, it is not always clear where the line is drawn. The overlap of laws drafted by the legislature and the jurisprudence of previous court decisions often means that an attorney with experience in evidentiary standards is necessary to determine what a court will or will not accept. Still, there are some general rules of thumb that may be applied when considering if a piece of evidence will be admissible or not in court. For example:
Hearsay – Testimony provided by a witness outside of a court proceeding which is meant to provide the truth of another witness’s testimony
Prejudicial Material – Any material that is beyond the facts of a case that might upset a jury is inadmissible
Non-Expert Testimony – Individuals who are not recognized by the court to be experts in a given field may not provide expert testimony
Improperly Gathered Evidence that was obtained illegally may not be used against you in court
Evidence in a DUI Case:
To secure a conviction against you in a Stanton DUI case, a prosecutor must prove beyond a reasonable doubt that you are guilty of the underlying offense. To that end, the prosecution must be able to show a jury that you were the person behind the wheel and that you were in violation of the applicable legal limit of Blood Alcohol Concentration (BAC) set by California.
Proving You Were the Driver:
There are several kinds of Evidence In A DUI Case that a prosecutor may try to prove you were the driver:
Testimony – Either from eyewitnesses or from a police officer
Your own words
Proving You Were Legally Intoxicated.
While testimony from eyewitnesses or your own admission may lead to probable cause for an arrest, proving that you were legally intoxicated usually requires chemical testing. This may come in the form of a blood, breath, or urine test. Generally, the test must show you had a BAC of 0.08%. However, if you are under 21 or you were on DUI probation at the time of the incident, you can face a DUI charge for having a BAC of 0.01%.
Challenging The Admissibility of Evidence in a DUI Case:
If you believe that a prosecutor may use inadmissible evidence against you, you have a right to challenge it. You, or your attorney, may file a Motion to Suppress Any Evidence that may not be reliable or relevant to the DUI charge you face. For example, there are several ways that a court may find the results of a breathalyzer to be inadmissible. If you consented to a preliminary alcohol screening before you were arrested but you were not told that the procedure was voluntary, you may challenge the results of that test. Likewise, if you have reason to believe that the device itself was not properly calibrated, you may be able to contest its results.
A DUI Attorney Can Navigate the Admissibility Standards:
A DUI charge can change the course of your life. As such, you owe it to yourself to make sure that you have the best defense possible against the charges. This means making sure that you can challenge the kinds of evidence that are inadmissible in your case. Fortunately, you don’t have to go it alone. We examine the evidence and find where it is weakest. If you think that you could benefit from a free consultation with an experienced attorney, don’t hesitate to call us.