Virginia Code sec. 9.1-1101 (b) (3) requires that breath alcohol test machines be tested and found to be accurate at least once every six months.
What happens if the prosecutor fails to prove that this actually happened? According to the Court of Appeals of Virginia . . . nothing.
According to the Court, prosecutors don’t have to prove a machine’s accuracy; rather, the defendant has the duty to introduce evidence showing that the breath test equipment was not properly maintained by the government and that this noncompliance with proper procedure resulted in a prejudice to his rights.