The Standard Field Sobriety Test (SFST) is given by police officers to drivers they suspect to be intoxicated. The test consists of three different parts: 1) the horizontal gaze nystagmus (HGN) test; 2) the one-leg stand test; and 3) the walk-and-turn test.
The SFST has existed since the 1970s, when police forces across the country began to crack down on drunk drivers more strictly. It has been scientifically validated as a way to determine a driver’s state of inebriation. South Carolina courts and other courts around the country will accept the results as evidence in court for the purposes of convicting a driver of DUI. Furthermore, and contrary to popular belief, a DUI conviction can occur on the basis of SFST results, even in the absence of breathalyzer test evidence.
The HGN test measures eyeball jerking when the driver tries to track something in the periphery of his or her vision. The walk-and-turn test and the one-leg stand test are something that sober people can easily perform, but inebriated individuals have a very difficult time doing. They also require drivers to perform a physical action while listening to instructions — something that is very hard for intoxicated persons to do.
A driver is not always convicted of DUI on the basis of failing a field sobriety tests. If you or a loved one were arrested and accused for DUI, it is important to look at all the facts and evidence being brought against you in order to determine the best strategy for your criminal defense. By speaking with a South Carolina DUI defense attorney, you can gather a sense for the most appropriate legal techniques to employ in your particular case.
Source: AAA DUI Justice Link, “Standard Field Sobriety Test,” accessed Nov. 23, 2015