One of the most common ways for the government to prove a person is driving under the influence is through the use of Virginia Code 18.2-266(i). See:  This section criminalizes operating a motor vehicle while having a blood alcohol concentration (“BAC”) of 0.08 or more.  If the BAC of the driver is 0.08 or more then Virginia Code 18.2-269(A)(3) provides “it shall be presumed that the accused was under the influence of alcohol intoxicants at the time of the alleged offense.” See:

This “permissive inference” allows the judge to infer you were impaired and puts the burden on you, the defendant, to prove you were not.  As you can imagine, this is a difficult task. So often one of the most important tasks of a good DUI defense is to find a way to invalidate or exclude the Certificate of Analysis (which is the evidence used in court to establish your BAC) from ever being presented to the judge for consideration. This article will focus on one of the ways to attack and hopefully prevent the Certificate of Analysis from being considered as evidence.

The Virginia Department of Forensic Science (specifically the Breath Alcohol Section) oversees the training and licensing of breath test operators, responding to requests for records, providing testimony in courts of law, and maintaining/certifying the Intox EC/IR II breath test equipment. The Intox EC/IR II is the breath test used in Virginia for determining your BAC.

It is essential for a DUI defense attorney to have a working knowledge of the Intox EC/IR II and the regulatory and statutory requirements that govern its use. One of the most important tools for attacking the BAC result listed on the Certificate of Analysis is to know the intricacies of the Intox EC/IR II Instructional Manual.

The last article we focused on the 20 minute observation period requirements in both the Intox EC/IR manual and the Virginia Code. This time the focus is on the accused’s ability to provide a proper

Once the officer has prepared the machine for the first sample the and the “please blow” prompt comes on the accused will only have three