Defending Blood Alcohol Test Results

Defenses related to the credibility of the prosecution’s blood testing evidence.

Before a blood test result may be admitted into evidence against you by a trial judge, the prosecutor must be able to cross several “hurdles” that your defense lawyer may raise.

At each point in the prosecutor’s offer of proof that the blood test was properly collected, stored, refrigerated and tracked (as it goes in and out of the laboratory’s refrigeration units), your defense attorney will be challenging the completeness and scientific propriety of each step.

For blood alcohol tests (as opposed to blood tests for drugs), it is essential that the blood be drawn in a correct manner, using a brown (betadine) or white (Hibaclens) soap rather than an alcohol pad or swab.

If alcohol is used to prepare your skin before the needle insertion, then this may artificially raise the alcohol content in the sample due to contamination. The blood tubes must be the correct ones, and must be handled correctly at every stage or any results can be challenged by your defense attorney.

Your attorney will use cross-examination of the prosecutor’s witnesses to start develop “reasonable doubts” in the minds of the jurors as to the scientific reliability of the evidence of this chemical test.

Then, expert witnesses may be called to testify on your behalf to show how the flawed handling of the blood may have resulted in a reading that is inaccurately higher than an accurate reading would have been. If the tests are not scientifically credible, then the measurement obtained by them should not be allowed as evidence against you at trial.