Challenging the Results of a Blood Test
Blood tests are widely regarded as the most accurate way to measure a suspected drunk driver’s blood alcohol content or BAC. But just because you “failed” a blood test does not mean that you will be convicted of a DUI. There are many ways an experienced DUI defense attorney can attack the results of your test.
The Board of Tests
The Oklahoma Board of Tests for Alcohol and Drug Influence governs all tests conducted for drug and alcohol impairment. This organization has set the standard by which all chemical tests should be administered.
Included in the Board of Tests’ guidelines are procedures for conducting blood tests. If these guidelines are not followed strictly by each person involved in the process of taking, transporting and analyzing your blood, your attorney may have grounds to challenge the results of your test.
Chain of Custody
Unlike a breath test where a sample is given into a machine that immediately produces a number, a blood test goes through what is known as a chain of custody. The sample is taken, stored, transported to a lab, tested and then the results are recorded.
If even one part of this chain is compromised, the results of the test should not be admissible. For example, if the person who drew the blood sample was not qualified or licensed to do so, the sample could have been taken incorrectly and may not be accurate. Or if the person who stored and transported the sample did not keep it at the proper temperature, the blood could have coagulated, rendering the results of the test inaccurate.