Margin of Error: Breath Testing & Legally Allowable Variances
Can a person's breath really be used to measure blood alcohol level?
The breath testing machine, or breathalyzer, you blew into contains some margin of error. Could this margin of error mean the difference between a conviction and a “not guilty” outcome? It is very possible. Also, was the margin of error so great in your case that no result can be relied upon? It is worth investigating these very real possibilities, since many breath test results are not accurate enough to be relied upon in court for these very reasons.
Your breath testing may not be accurate enough to be relied upon in court
Another source of error involves the difference between the breath test results themselves. A wide disparity between your breath test results may show that the machine incorrectly and inaccurately recorded your blood alcohol level. If, for example, there is a major numerical difference between the first and second breath sample result, the machine you blew into may be malfunctioning and incorrectly recording evidence against you.
The purpose in asking you to blow into the device more than once is so the police can verify that the results are close enough to each other in accuracy. If these numbers are widely different, you may be able to demonstrate the variance between your results shows that neither result is accurate. If you can show that the testing machine produced results that cannot be verified for accuracy, the court may prohibit the use of these results in court.
Breath Testing Defenses Are Important
If so, you have once again created another reason for the prosecutor to make concessions for you that are not available for other folks that were unaware of this defense tactic. Ask your lawyer for information regarding the legally allowable variances for breath test results. You may be happily surprised to learn that key evidence against you may be removed from the case.