Police officers who stop people for the suspicion of drunk driving are tasked with finding out how impaired a driver might be. There are only limited ways that they can do this on the side of a road, so they have to make the most of what they have.
There are two primary things that the officers can do when they think you are impaired. One of these is to do a field sobriety test, which can help them to determine whether you are intoxicated. The other is using a preliminary alcohol screening device.
The PAS device is what you often see on television. It is a handheld device that tests a person’s blood alcohol concentration percentage. It isn’t the one that is used in court. Because these aren’t calibrated in the same manner as the official larger breath testing devices that are stationary, they aren’t considered accurate enough to support criminal charges.
When the officer is determining whether to arrest you or not, they won’t rely solely on the results of the PAS. Instead, they put together all the information that is available at the scene. If you did take a field sobriety test, the results of that will be considered. Other factors like the smell of alcohol on your breath or spotting an open container in your vehicle also help the officer to make the determination.
You should know your rights if you are pulled over for any reason, including the suspicion of driving drunk. Your actions, as well as those of the officer, can have an impact on the defense strategy you present in court.