California implied consent laws require drivers to submit to a chemical test of their blood or breath to determine blood alcohol content. The law applies to individuals lawfully arrested for driving under the influence. If a blood or breath test is unavailable, the law presumes the person consented to a urine test.
Failing to submit to a chemical test after a DUI arrest in California results in an administrative 1-year driver’s license suspension by the California Department of Motor Vehicles. A second offense of failing to submit to a chemical test after DUI arrest is a two-year revocation of driving privileges.
Law enforcement officers often give evidentiary breathalyzer tests at the police station. Breath testing in this manner is admissible as evidence in court. However, the officer may also take a blood sample to determine the person’s Blood Alcohol Concentration (BAC) level. It can be more difficult for a defendant to challenge the results of a blood test, but it is possible with independent tests.
A police officer cannot force you to take a blood test unless the court issues an order requiring the blood test. However, the penalties for refusing to submit to a chemical test would apply even if the court ordered the person to submit to the blood test.
What Is a Blood Split in a California DUI Case?
A police officer may give a person a choice between a breathalyzer test or a blood test after a DUI arrest. Many people choose a breathalyzer over a blood test after being arrested for drunk driving. However, there are times when a blood test is required.
Blood tests after a DUI arrest are required when:
- The driver cannot complete a breathalyzer test because of a medical condition or physical impairment
- The officer suspects that the person is driving under the influence of drugs
- An evidentiary breathalyzer is not available for use
Title 17 of the California Code of Regulations (17 CCR §1219.1) explains blood collection and retention for compliance with California Vehicle Code §23158. It directs that the person collecting the blood sample to collect enough blood for multiple tests. The second sample is preserved and turned over to the driver upon request for independent testing.
How Does a Defendant Obtain a Blood Test Sample After a DUI Arrest?
The person’s DUI defense attorney generally requests that the prosecution provide a portion of the blood sample for independent testing. Generally, the state agrees to provide the sample to the DUI attorney. However, if the prosecutor refuses or fails to comply with the request within 15 days, the DUI defense lawyer files a motion with the court.
The “blood split motion” requests the court to order the prosecutor to produce a sample of the defendant’s blood for independent testing. The court may also sanction the prosecutor for failing to provide the sample to the defendant. Sanctions could include preventing the use of the chemical test results at trial and contempt proceedings against the prosecutor.
After having the blood tested, you do not have to use the results at trial. If the results favor the prosecution, you do not have to disclose that information to the prosecution. However, if the independent testing of the blood sample returns results that help your case, you may include that evidence as you defend yourself against DUI charges during the trial.
How Can a Blood Split Motion Help Your DUI Defense?
Under California Vehicle Code §23152, you can be charged with drunk driving if:
- You operate a motor vehicle with a blood alcohol content of .08% or more; OR,
- You drive a vehicle under the influence of any alcoholic beverage
Experienced California DUI lawyers use the results of independent blood tests to fight drunk driving offenses under both situations.
Fighting a California Per Se DUI Case
California “per se” DUI cases rest on the fact that the person’s BAC was above the legal limit of .08%. The prosecution uses the evidentiary blood test to prove that you had a BAC greater than the legal limit at the time of your arrest. The law presumes that you were too intoxicated to operate a motor vehicle if your BAC was above the limit.
It is important to remember that the legal limit for a drunk driver may be lower for specific drivers. For example, the legal limit for commercial truck drivers is a BAC of .04% or higher. Underage DUI (driving under the age of 21 years) has a legal BAC limit of .05% or higher. Ride-share, taxi, and limo drivers have a legal limit of .04% or higher.
If the independent test reveals a BAC of below the legal limit, the defense can argue that the driver was not impaired at the time of the DUI traffic stop. The argument can create reasonable doubt, which might be sufficient for a jury to find the defendant not guilty.
Fighting Charges of Driving Under the Influence of Alcohol or Drugs
The other DUI offense relies on the prosecution proving that the alcohol in your system impaired your ability to operate a motor vehicle safely. If the charge is DUID (driving under the influence of drugs), the prosecution must prove that the drugs in your system impaired your driving abilities.
Experts disagree on what levels of alcohol or drugs impair a person’s ability to drive a vehicle. Because each person’s physiology is different, it may take more or less of a substance to impair your ability to drive than it would another person.
Defendants use the results of an independent blood test with the totality of the evidence to argue they were not impaired while driving.
For example, the only legal evidence is the police officer’s testimony that he smelled alcohol and the person “appeared” drunk because the driver refused to take the field sobriety tests. A blood split motion resulted in a low BAC level on an independent test. Along with expert testimony, there could be sufficient doubt for the jurors to find the defendant not guilty.
If the defendant is facing DUID charges, an independent test can be helpful for the defense. There is no “legal limit” for the amount of drugs in a person’s system to presume they are impaired. Therefore, it is more difficult for the state to win its case if the only evidence of drugged driving is a blood test that the defense refutes through independent testing.
Challenging the Collection Methods of a Blood Test for a DUI Charge
Title 17 clearly defines how blood samples are to be collected in a DUI case. The procedures law enforcement officers must follow to collect blood samples after a DUI arrest include:
- A medical professional or authorized technician must collect blood
- The sample must be collected as soon as possible after the arrest
- A sufficient sample must be collected to allow for testing by the state and by the defendant (i.e., blood split)
- The vial must have sufficient preservative and anticoagulant
- The blood cannot be contaminated with other substances
A DUI defense may include challenging the results of a DUI blood test because the officers failed to follow Title 17 procedures when collecting or preserving the blood samples.
Can You Split a Breath Sample or Urine Sample for a DUI Case?
You cannot split breath samples. Therefore, there is no way you can refute the results of a breath test except to challenge the circumstances surrounding the breathalyzer test.
For example, you could argue that the breathalyzer malfunctioned or was not calibrated correctly. In addition, you could offer evidence that the police officer was not trained or performed the breathalyzer incorrectly. Also, you could argue that a medical condition or other factor caused a false BAC reading from the breath test.
However, urine samples can be split for independent testing. Title 17 has similar requirements for collecting urine samples after a DUI arrest:
- The urine sample must be large enough to allow for at least two tests
- The urine sample must be retained for up to one year after collection to allow for independent testing by the defendant
Urine tests are not standard in DUI cases. Instead, most defendants are required to take breath or blood tests. Urine tests are only used when the other two tests are not possible.
Fighting Chemical Tests After a California DUI Arrest
Independent lab results could show that blood tests performed after a DUI arrest were incorrect. Your test could result in a BAC lower than the legal limit or the limit found by the police lab. In some cases, the independent lab may find that the blood sample had been contaminated or fermented, invalidating the results. Samples that were mishandled or not refrigerated properly could also provide incorrect BAC results.
Working with an experienced California DUI defense lawyer is the best way to attack the results of a chemical test after a DUI arrest. An attorney examines all evidence gathered by the state to determine what challenges would be helpful in your defense. Never assume that a blood test or breathalyzer result means a guilty verdict until you discuss your case with an attorney.