Breath and Blood Test Results in DUI Cases

Posted by Robert Berglund | Nov 21, 2016 | 0 Comments

The California Vehicle Code sets out "per se" blood alcohol content amounts that create a rebuttable presumption that a person's ability to drive is impaired and, therefore, that they are under the influence.  The legal limits are .08 percent for all drivers and .04 percent for commercial vehicle drivers.  If you were arrested for Alcohol DUI and gave a breath or blood test over these limits, you will most likely be charged with a criminal DUI offense and have a DMV Administrative Per Se action initiated against you.  (Note that drivers under the age of 21 can have their drivers' license suspended for being .01 percent even if they were not arrested for DUI and face no criminal charges.)  However, this presumption is not conclusive and can be challenged by a good DUI lawyer. California Code of Regulations Title 17 regulates the administration of breath and blood tests in DUI cases.  

Breath testing devices are far from perfect and are subject to error, just like any machine.  If they are not properly maintained, regularly checked for accuracy, and calibrated properly they may give incorrect readings.  For example, a person who gave a breath test result of .10, which is over the .08 legal limit, may actually only have been a .05 and under the legal limit.  This erroneously high reading can make the difference if a jury is deciding whether or not a person charged with DUI is guilty or not guilty.  California law requires law enforcement agencies to keep records of breath testing equipment used in DUI cases.  A good DUI defense lawyer can review the breath test machine's accuracy, calibration, and maintenance records and determine if the machine was functioning properly at the time the driver was given the breath test.

Similarly, blood test results can be compromised if the blood sample is not drawn and maintained properly prior to testing.  California DUI law requires the blood sample to be drawn in a medically approved manner and to be maintained properly to avoid contamination prior to testing.  Mistakes made by medical personnel drawing the blood, for example swabbing the person's arm with an alcohol based solution, can result in false positives or elevated alcohol percentage readings. Mistakes made in the handling of the blood vial can further compromise the accuracy of the test.  For example, if the temperature of the blood vial increases or fluctuates then fermentation can occur.  Fermentation is the process by which alcohol is formed from bacteria, yeasts, and other microorganisms within the blood. If fermentation occurs prior to the testing of the blood sample, the test result will show a higher blood alcohol content than what the person's blood alcohol content actually was.  An experienced DUI lawyer, with the assistance of a toxicology expert, can review the blood draw and analysis records to determine if the blood sample was contaminated and the blood test result was compromised.  

If you have been arrested for DUI and given a breath or blood test resulting in a result of .08 or greater do not assume that you are guilty of DUI.  There are many issues that may effect the accuracy of the test results.  CONTACT Berglund Law Office, P.C. today for a free and confidential consultation.  Los Angeles DUI Lawyer Robert D. Berglund will personally return your phone call to discuss your case and answer any questions that you may have.

About the Author

Robert Berglund

Attorney Robert D. Berglund specializes in representing persons arrested on suspicion of Driving Under the Influence of alcohol or marijuana...


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