In North Dakota, when a police officer or patrolman suspects that a person is driving while intoxicated, they must first establish probable cause before they can make an arrest. Most of the time, an officer will establish probable cause by pulling the driver over and asking them to perform one of several standardized tests. Knowing what to expect during the stop may help a driver perform the tests without stress or anxiety, which can potentially produce a more accurate result.
There are typically three sobriety tests that officers often perform. The first is the horizontal gaze nystagmus, which is an eye test. The officer moves a flashlight in front of an individual’s face and asks the person to track the light with his or her eyes. The officer is looking to see whether the person’s eyes stay with the light. The officer is also looking to see whether the individual’s eyes react to jerks in the light as a sober person’s eyes normally would.
The other two field sobriety tests are called divided attention tests. One requires a person to walk heel-to-toe along a straight line before turning on one foot and walking back along the same line in a similar fashion. In the other test, the person must stand on one foot and count by thousands. In either test, the officer is looking to see whether the person can keep their balance, follow directions and complete the task. A failure to do any of these could be cause for an officer to suspect intoxication.
There could be a number of reasons why a person may fail one of these tests, including prescription medications, poor instructions from the officer or even just the officer misinterpreting the results. This information should not be confused for specific legal advice; a defense attorney might be able to analyze police reports and even challenge the information in court.
Source: National Highway Traffic Safety Administration, “The Highway Safety Desk Book”, November 22, 2014