Contact Us for a Free Consultation 714-721-4423

Blog | The Law Office of Richard Wagner

Understanding DUI Blood Tests in California

Posted by Richard Wagner | Apr 06, 2023

Can I Challenge DUI Blood Test Results?

Drunk driving or drugged driving in California is a serious criminal charge. During a DUI investigation, an officer may request a blood sample.

Photo by Nguyen Hiep on Unsplash

blood test alcohol drugs

This is especially true when an alleged suspect refuses a breathalyzer test or a police officer believes the suspect is intoxicated by drugs.

If you do not agree to it, the police will get a search warrant, and at that time, a blood sample will be taken with or without your consent.

A lot of confusion surrounds what your rights and obligations are regarding drunk driving and blood tests.

To do one thing and not the other can have a significant impact on any criminal charges filed against you or DMV penalties imposed on you in California.

DUI Defense Attorney Richard Wagner wants to ensure you are informed and understand both your rights and the consequences that flow from missteps taken when encountering the police during a DUI investigation in California. Contact him today at (714) 721-4423 to schedule a FREE Consultation. 

What are DUI Blood Tests?

DUI blood tests are chemical tests used in California at the direction of the police to determine whether and to what extent an individual unlawfully has alcohol or drugs in their system. It is used most often in three circumstances:

  1. The alleged drunk driver has refused a breath test; and/or
  2. The police believe the driver might be under the influence of drugs, which can include prescription medication or any type of illicit drug;
  3. The alleged drunk driver has chosen to take the blood test rather than the breath test after being arrested for DUI. 

A blood test is also much more intrusive than a breath test. With breath tests, you simply blow into the testing machine. With urine tests, you urinate into a cup. With blood tests, however, a qualified medical professional must draw blood to collect a test sample.

Can I Refuse a Blood Test in California?

The simple answer is yes. Keep in mind, however, that a refusal in California can have significant consequences. The same is true even if you are never convicted of an intoxicated driving offense in California because you will still be face DMV administrative penalties.

The problem is this: VC 23612 the implied consent law.

When you get a driver's license and drive anywhere in California, you have implicitly implied to agree to obey the laws of California. Basically, by agreeing to obey the rules of the road, you also implicitly agree to chemical tests. However, the United States Supreme Court in Missouri v. McNeely (2013) 569 U.S. 141, transformed implied consent laws, holding you can withdraw your consent to a blood draw. 

When Are DUI Blood Tests Allowed in California?

Unless the prosecution can prove that there were exigent circumstances, or you gave lawful consent, or the police got a search warrant, the police cannot force you to give a sample of your blood.  

  • Exigent Circumstance - natural dissipation of alcohol in blood must be determined on a case-by-case basis
  • Express Consent must be without coercion
  • Implied Consent - Prosecutor must prove by preponderance of evidence by your conduct or statements. Also, California has an implied consent statute VC 23612. However, you may withdraw the VC 23612 consent. 

Thus, if you are arrested for drunk driving and are asked to whether you will take a breath or a blood test but refuse, there are DMV administrative penalties in play. These penalties include license suspension or revocation with no ability to get a restricted license.

If you do refuse to give a blood sample (or refuse a breath sample), the police usually get a warrant to collect your blood sample. In the end, if you refuse, you will likely still have to give a blood sample.

Can a DUI Blood Test In California Be Wrong?  

Blood tests can determine blood alcohol content (BAC) level and it can also identify specific drugs and the amount of those drugs in your system.

However, they can still be unreliable when certain issues are present.

Common situations that lead to reliability issues with a blood test result in DUI cases in California include:

  • Too long of a waiting period between arrest and administration of the blood test
  • Microbial contamination of the blood sample - Fermentation 
  • Improper preservation or storage
  • Improper transportation of the sample
  • Gap in the sample's chain of custody
  • Human error (sample mix-up, mislabeling during analysis)
  • Drawing of the blood sample by an unqualified person
  • Not drawing the blood sample according to accepted medical practices

In addition, the technology and machines used to analyze the blood samples could have problems making the results unreliable. Instrumental factors such as detector, injector, and/or temperature variations can affect accuracy. These machines require regular maintenance but are often neglected. 

Fermentation in the blood vial?

Alcohol can be made on its own in the blood vial through what scientists called Fermentation. This is when the glucose in your blood combines with microorganisms causing alcohol to be be produced. The machines crime labs use to test your blood cannot tell if the alcohol found in your blood came from fermentation or from the alcohol you consumed.  

DUI defense attorneys in California who have the right experience, knowledge, and skill in these types of cases will be able to identify unreliable blood test results. Motions can be timely filed and strategic cross-examination of the relevant witnesses can be used in your defense.

How DUI Defense Lawyers Beat DUI Blood Tests

DUI blood tests can be disputed and challenged under certain circumstances. A defense lawyer should identify when those circumstances are present and take appropriate action.

With DUI blood tests your defense attorney can file motions to show the conditions:

  • subjected you to “unjustified element of personal risk of infection or pain" People v. Ford (1992) 4 Cal.App.4th 32, 38.
  • and evaluate whether “the draws were performed in a manner which created undue harm or risk .” People v. Mateljan, (2005) 129 Cal.App 4th 367, 376 and,
  • Whether you were "exposed to an unreasonable risk of infection or pain?” People v. Sugarman, (2002) 96 Cal. App. 4th 210, 216 

The phlebotomist must have taken your blood in a reasonable manner according to acceptable medical practices. 

To determine whether your blood draw was taken in a reasonable manner, consider whether: 

  • the phlebotomist washed their hands with antibacterial soap and water
  • you were seated comfortably in a chair - not standing as there is a danger of fainting or you moving
  • your arm was supported firmly
  • your arm was bent at the elbow
  • your arm was extended so as to form a straight line from the shoulder to the wrist 
  • the tourniquet was left on your arm for more than one (1) minute 
  • the median crucial vein was used 
  • the person drawing the blood cleansed the area thoroughly to prevent contamination
  • only Aqueous Benzalkonium Chloride, (“Zephiran”), Aqueous Merthiolate, Aqueous Mercuric Chloride, or Povidone-Iodine (“Betadine”) was used - alcohol cannot be used 
  • the area was allowed to dry
  • if it is necessary to repalpate the site, the gloved finger was also cleansed so the site was not contaminated
  • the cover of the needle was not removed until ready to draw the blood, thus avoiding needle contamination
  • the cover was removed from the needle and examined, especially the tip to determine if it was free of hooks
  • the vein was entered with the vial in a downward position 
  • the vial was filled until the vacuum was exhausted and blood flow ceased 
  • after completion of the draw, the blood vial was gently inverted six to ten times
  • the phlebotomist did not probe unnecessarily on your arm with a needle. They should not stuck you more than two (2) times

Finding the right DUI defense lawyer in California will be key to a successful outcome in your DUI case.

Contact a Skilled DUI Defense Attorney in California Today

DUI Defense Attorney Richard Wagner understands the complex nature of California intoxicated driving laws, the technical and scientific aspects of blood tests, and how to strategically fight the allegations to get the best outcome in your unique case.

He wants you to know that just because you are charged with DUI offenses, it does not mean you will be found guilty. You can successfully defend against these types of charges, but you need an DUI defense lawyer who can help you do it. Call him today at (714) 721-4423 or fill out an online form to schedule a FREE Consultation.

About the Author

Richard Wagner

Attorney Profile Defense Lawyer Richard Wagner upholds and defends freedoms and liberties enshrined in our United States and California Constitutions.  “Richard was able to achieve an even better outcome for my case than what we initially thought was possible. I couldn't be more grateful to h...

Contact Richard Wagner Today

Irvine Office
7700 Irvine Center Drive, Suite 800
Irvine, CA 92618
Rancho Cucamonga Office
9431 Haven Avenue
Rancho Cucamonga, CA 91730