DUI / OWI Breath Testing
Driving Under Influence / Operating While Intoxicated Law
Alcohol Breath Testing in Indiana
First, it is important to understand that you will likely be offered two different types of breath tests during a DUI investigation. The Officer will first request that you submit to portable breath test (PBT). No one is required to submit to such a test and there is no penalty at law for not doing so. The actual result of the PBT is not admissible at trial against you, but the mere fact that a positive reading for alcohol occurred is admissible. In other words, the investigating officer cannot testify that you were .15 on the PBT, but he/she can testify that the instrument detected the presence of alcohol in the system. The PBT is used by officers to help establish probable cause to detain you and further the DUI investigation.
At some point during the traffic stop, the officer will likely request that you submit to a certified chemical test. This is the instrument that is typically located at the county jail/Sheriff’s Dept. and is the machine that provides the official reading which will support a DUI charge against you.
Generally speaking, there are two different certified chemical testing machines used across the state of Indiana, the Datamaster and Intoximeter EC IR2. Each county may choose which machine they desire to utilize. They each have their own mechanical differences but both basically function under the same “scientific” theories. The primary difference between the two instruments is that the Intoximeter requires the accused to provide two breath samples and records the lowest of the two samples as the official reading, whereas the Datamaster requires and records one sample.
If the certified machine generates a reading of .08 or greater you will likely be charged with the formal charge of Operating a Vehicle with a BAC of .08/.15 or greater, depending on the amount in system. If the officer believes you exhibited other indicators of intoxication/impairment, you may be charged with the formal charge of Operating While Intoxicated.
The most important aspect of understanding the significance of a “failed” breath test (.08 or greater) is to understand that the State must prove that your blood alcohol level was .08 or greater at the time you last operated the vehicle. This could be several minutes and even more than an hour before the time of the test, depending on the circumstances. If the test is completed within 3 hours of the time you last operated the vehicle, the State is entitled to an instruction that essentially tells the jurors that they may presume your blood alcohol level (per the machine result) was the same at the time you drove. This shifts the burden of proof to the accused to raise reasonable doubt that the amount of alcohol in his/her system at the time of operation did not equal or exceed .08. This brief review of the nuances of alcohol breath testing demonstrates the complexity of DUI law in Indiana.