DWI Breath Test Observation Period

When a driver gets arrested for a DWI, an officer takes them back to the station and requests an official test to determine the driver’s alcohol concentration level. In the vast majority of cases, the test offered is a breath test, administered by the State’s DMT machines (DataMaster). The driver provides two breath samples into the machine, at which point the “true” alcohol concentration value is determined by taking the lower value from the two samples, rounded to the nearest hundredth. If the sample comes back at .08 or more, the driver will be charged with a DWI.

For the defense, this test result can be challenging to defeat if it’s administered properly. And this is the crucial part – it must be administered consistent with the proper procedures required by the machine manufacturer and the State BCA. You’d be surprised at how frequent simple and/or lazy mistakes are made in the administration of the test, particularly during the ‘Observation Period,’ which can be critical to raising a proper defense.

Mistakes During the Breath Test Observation Period

The Observation Period is a mandatory step for the officers to take. It requires that the officers observe the driver for a minimum of fifteen-minutes prior to having him or her provide their breath samples. The idea behind this is that mouth alcohol can lead to artificially inflated test results. The risk of the presence of mouth alcohol erodes after fifteen-minutes, or so the theory goes. So, in order for the testing process to be done correctly, the officer must keep constant contact with the driver and is looking for any burping, belching, vomiting, etc. that might cause the presence of mouth alcohol. If this is not done properly, the State may not be able to lay proper foundation that the testing process was properly administered, leading to the suppression of the results as a consequence.

To understand this better, let’s review a common error that we find in our practice. A driver gets arrested and transported back to the station for the breath test. The driver is read the Breath Test Advisory and immediately agrees to a breath test. The officer immediately administers it. No problem. Except, when you review the paperwork, you discover the observation start time – which must be inputted into the DMT in order for it to run – is the time of the arrest (or even the time the driver was stopped – not kidding, we’ve seen this). This means that the observation period is somehow conducted while the officer is driving back to the station. Doesn’t seem like a proper observation period can be done then, right? Correct. And courts have suppressed results when this is the case because it effectively negates the requirement of a proper observation period.

Speak With a DWI Attorney for Help Today!

Understanding this amount of detail and what is required of officers in properly effectuating a DWI arrest is what we do at North Star. And if you are facing a DWI, you want a team that knows these nuances and how to use them to your advantage when possible.