Fresno DUI Lawyer Jonathan Rooker is one of the few DUI Attorneys in the Fresno and Greater Central Valley region who has in depth scientific knowledge of Gas Chromatography.  Gas Chromatography is used to separate molecules.  In terms of DUI's, this is the method used to test blood of a person arrested, cited, and/or charged with a DUI.  Practicing Criminal Defense in Fresno, especially being one of the most specifically educated DUI Defense Attorney's in the area of science behind the DUI blood tests, Jonathan takes an active approach to gaining more education on the subject.  Science is a DUI Lawyer's friend, and Jonathan believes that science is on our side in DUI cases.

How does blood testing work?

Following an arrest, blood is drawn from the client, and placed in a tube.  The tube should have an anti-coagulant and preservative in it prior to the blood being placed in the vial.    This is important because when blood coagulates, or clumps up, the alcohol does not coagulate.  This means the remaining blood has a higher level of alcohol in it, which will cause the result to be over stated.

If the preservative is not present in large enough concentrations, the blood may begin to ferment.  Fermentation actually causes the sugar, or glucose in the blood to begin a process of fermentation, or converting the sugar to alcohol, much as the sugar in grapes is fermented to form alcohol in wine.

Next, the blood is stored and/or tested.  In DUI Cases this important.  What temperature was the blood stored at?  How long?  What is the chain of custody?  All important questions in DUI cases.  DUI prosecution in Fresno typically involves a gas chromatograph testing of the blood.  The print out is the chromatogram, which shows peaks representing the volatile substances that exit the chromatograph at specific times.  Sometimes there are unidentified peaks in the chromatograms, which are possible indicators of degradation of the tube in the machine, testing of decomposing samples, contamination, fermentation, and/or many other factors.  In short, it may not be a clean test of the subjects blood, or even representative of the true Blood Alcohol Concentration of the blood at the time it was drawn.

If I got a DUI in Fresno and chose a blood test, can I high a DUI Lawyer to fight the case?

YES. People all too often believe if they took a blood test, and it says they were .08 BAC or more, there is not way to fight the test.  However, like anything else, there are many arguments, facts, scientifically valid approaches to discrediting the governments laboratories work.  Every machine has a range of accuracy and precision if properly used.  If the machine, the methods, calibrations, and human factors are brought out, you can, and many people do successfully defend cases involving blood tests where the results are over .08.

Many laboratories do not run blank samples between each subject.  A chromatagraph can have dozens of samples placed inside it for testing, left for hours, and later return to find the results printed up.  However, they machine uses what is called an, "auto sampler" to extract the blood, or in some cases the gas at the top of the vial, then inject it into the chromatograph.  When no blank is ran in between samples, how can one be certain that contamination from the prior samples didn't occur?  Ask yourself, would you be comfortable with eh same needle being inserted into your skin after it was removed from a bottle of blood from an unknown source directly before being inserted into you veins or arteries?  Would you trust the government laboratory that claims there is no contamination?  Why should a jury believe them either.