When a DWI arrest is made, there are three phases a suspect and officer must go through. The first phase deals with the motion of the vehicle where the officer will observe suspicious driving such as weaving, swerving, or any other type of traffic violation. When the officer has a proper basis to pull the driver over, he will observe these clues to establish whether the driver is impaired. This is where the second stage comes in. An officer will smell for the odor of alcohol, look for red and glassy eyes and finally slurred speech.
Next, if the officer believes the driver to be impaired, he will perform field sobriety tests. These tests include (1) the eye and pen test; (2) the walk and turn; and (3) the stand on one leg and touch your finger to your nose test. The NHTSA manual lays out the foundation for all of these tests. Therefore, when the officer has subjected a driver to all three of these tests, and the driver does not pass, the officer will have probable cause to bring that person into the station.
