There are a number of methods Virginia police use when determining whether a driver is under the influence of alcohol. For example, a driver might be asked to submit to a Breathalyzer or blood test, which measures blood alcohol content. In other situations, an officer might ask a driver to perform a series of field sobriety tests when deciding whether to make an arrest for drunk driving.
3 types of field sobriety tests
The National Highway Traffic and Safety Administration — NHTSA — endorses the Standardized Field Sobriety Test — SFST. The SFST consists of three different tests that can be performed during the course of a traffic stop. These are:
- The horizontal gaze nystagmus
- The walk-and-turn
- The one-leg stand
When an officer performs the horizontal gaze nystagmus test, he or she is checking for involuntary jerking of the eyes when looking to the side. Although this occurs naturally, it is exaggerated in those who are intoxicated. The walk-and-turn test allows an officer to observe how well someone can perform a task with divided attention, and involves asking a driver to walk a straight line and back, usually heel to toe. The one-leg stand measures someone’s balance, and an officer performs this test by asking a driver to stand on one foot for approximately 30 seconds.
Virginia police officers often use the results of field sobriety tests to seek BAC testing or to even make arrests. However, the results of these tests are subject to human interpretation, meaning that arresting officers can get things wrong sometimes. Those who have been arrested and charged with drunk driving because of field sobriety test results may want to consider whether challenging those results could be in their favor.