Officers receive training when they are in the academy about how to conduct DWI investigations, and they look for a many things. They are trained to look for:
- how the person is driving
- how the person stops
- how the person exits their car
- how the person interacts with the officer
- bloodshot, watery eyes
- slurred speech
- an odor of alcohol
Then they do a whole battery of tests called the Standard Field Sobriety Test, which includes having you follow a pen with your eyes, walk in a straight line, and having you stand on one foot. They are trained to detect what they call “clues” from each of those tests to determine whether you are intoxicated or not.