Breathalyzers in Manassas DUI Cases

Despite the fact that breathalyzers are used in most DUI cases, there are a wide array of problems which may arise with the machines that are typically used. Below a Manassas DUI lawyer discusses these problems and what factors can lead to an erroneous breath test. For more information on how this might affect your case, call and schedule a consultation today.

Reliability of Breathalyzers in Manassas

About five or so years ago, the Virginia upgraded to a new model of testing called the ECIR2. Unfortunately for Virginia drivers, this machine is still rather behind the times when it comes to breath testing vis-a-vis other jurisdictions.In general, breath tests are reliable, however with that said the Virginia instruments are lacking in terms of being specific to someone’s BAC.

Common Misconceptions Regarding Breathalyzer Tests

The most common misconception is that they’re always accurate. Even the Department of Forensic Science has recently acknowledged that there is a margin of error in every single sample analyzed by the ECIR2.  

Factors That Can Lead To Inaccurate BAC Scores

There are a number of factors that can absolutely lead to inaccurately high BAC scores. The machine used makes certain scientific presumptions about the person who’s giving the test. For starters, it assumes that the person being tested has a certain body temperature and a certain mouth temperature. It doesn’t test for that even though it could easily do so. If the person is being tested for alcohol and they’re blowing into this machine with a fever, even if it’s a relatively low-grade fever, the test result is going to be too high. It is not going to be accurate and any expert can verify that.

Furthermore, it makes an assumption about a person’s partition ratio. Partition ratio has to do with the ratio of blood cells in your blood. If you look at the breath sheet you get after taking a breath test on the ECIR2, it tells you that your level of intoxication is point whatever per 210 liters of breath. That ratio is per 210 liters of breath and is directly related to this partition ratio, which on average, according to the government, is 2100:1. However, any expert will tell you that a person can vary greatly with their partition ratio. Most experts will tell you that the partition ratio in any one person on any given day can fluctuate between about 1800:1, to 2500:1. Because they’re not testing the person’s blood, there’s no way the government can possibly know what the partition ratio is.

That’s just two ways that the breath test can be off and it can be off very easily due to those two variables. If a person has a partition ratio that’s off and they have a high fever or even a low-grade fever, the test can be inaccurate.

Calibration of Breath Test Machines

DFS’ specific protocols on the calibration and testing of these machines need to be done every six months. However, one issue that does come up occasionally is if a machine has some sort of repair or some sort of part that’s replaced inside the machine. If we can establish that a part or repair is integral to the accuracy of the machine and that it is not calibrated correctly after that repair or replacement, then that questions the reliability of the machine at the time the test was given.

Challenging Breath Test Results

An attorney can challenge breathalyzer results and typically do so all the time. Unfortunately, most judges will not suppress the evidence altogether unless there’s a glaring problem with the procedure or something similar. Often judges will say, “that information is interesting and it goes to the weight of the evidence, not its admissibility.” This essentially means you can argue to the judge that whatever flaws found in the testing system or any mistakes in the scientific assumptions made by the machine counts towards the weight of the evidence and how strongly the judge should consider that evidence as proven fact.

Other Things People Should Know About Breathalyzers in Manassas

I think people should know that simply because they’re being charged with DUIs and just because here’s a sheet of paper saying they’re 0.08 or higher doesn’t mean it’s necessarily true. If there are issues or discrepancies, we can find them. If there’s a way to question the reliability of that test, we will find it.