The Standardized Field Sobriety Test (SFST) battery is composed of three tests: Horizontal Gaze Nystagmus (HGN), Walk-and-Turn (WAT), and One-Leg Stand (OLS). The tests were developed by the National Highway Traffic Safety Administration (NHTSA) in the late 1970′s. In 1981, law enforcement officers began using NHTSA’s Standardized Field Sobriety Test (SFST) battery at roadside to help determine whether motorists who are suspected of DWI have blood alcohol concentrations (BACs) greater than 0.10 percent. Since 1981, however, many states including Texas have implemented laws that define DWI at BACs below 0.10.
HORIZONTAL GAZE NYSTAGMUS
“Nystagmus” means an involuntary jerking of the eyes. HGN refers to an involuntary jerking occurring as the eyes gaze toward the side. In addition to being involuntary the person experiencing the nystagmus is unaware that the jerking is happening. The theory behind the test is that nystagmus becomes readily noticeable when a person is impaired.
Officers frequently fail to properly administer the HGN. It is crucially important for your attorney to review the videotape, if available to ascertain whether the test was properly administered or whether suppression of the results is possible.
WALK & TURN
The WAT is a divided attention test consisting of two stages: Instruction Stage; and Walking Stage. In the instruction stage, the subject must stand with their feet in heel-to-toe position, keep their arms at their sides, and listen to instructions. The subject must maintain the heel-to-toe position and may not begin walking until all instructions are given. In the Walking Stage the subject takes nine heel-to-toe steps, turns in a prescribed manner, and takes nine heel-to-toe steps back, while counting out loud and watching their feet.
ONE LEG STAND
The OLS is also divided into two stages. In the Instruction Stage, the subject must stand with feet together, keep arms at side and listen to instructions. In the Balance and Counting Stage, the subject must raise the leg of his choice approximately 6 inches off the ground, toes pointed out, keeping legs straight. While looking at the elevated foot, count out load in the following manner: “one thousand and one”, “one thousand and two”, etc, until told to stop. The officer will instruct the subject to stop after 30 secondsThe Standardized Field Sobriety Test (SFST) battery is composed of three tests: Horizontal Gaze Nystagmus (HGN), Walk-and-Turn (WAT), and One-Leg Stand (OLS). The tests were developed by the National Highway Traffic Safety Administration (NHTSA) in the late 1970′s. In 1981, law enforcement officers began using NHTSA’s Standardized Field Sobriety Test (SFST) battery at roadside to help determine whether motorists who are suspected of DWI have blood alcohol concentrations (BACs) greater than 0.10 percent. Since 1981, however, many states including Texas have implemented laws that define DWI at BACs below 0.10.
HORIZONTAL GAZE NYSTAGMUS
“Nystagmus” means an involuntary jerking of the eyes. HGN refers to an involuntary jerking occurring as the eyes gaze toward the side. In addition to being involuntary the person experiencing the nystagmus is unaware that the jerking is happening. The theory behind the test is that nystagmus becomes readily noticeable when a person is impaired.
Officers frequently fail to properly administer the HGN. It is crucially important for your attorney to review the videotape, if available to ascertain whether the test was properly administered or whether suppression of the results is possible.
A pie y a su vez
El WAT es una prueba de atención dividida que consta de dos etapas: la etapa de instrucción; y caminando de la etapa. En la etapa de instrucción, el tema debe permanecer con sus pies en posición de talón a los pies, mantener sus brazos a los lados y escuchar las instrucciones. El sujeto debe mantener la posición de talón a los pies y no empezar a caminar hasta que están dadas todas las instrucciones. En la etapa de caminar el tema toma nueve pasos de talón a los pies, se convierte en una forma prescrita y toma nueve pasos de talón a los pies, mientras contando en voz alta y ver sus pies.
UN STAND DE PIERNA
La operación también se divide en dos etapas. En la etapa de instrucción, el sujeto debe permanecer con los pies juntos, mantener armas al lado y escuchar las instrucciones. En el equilibrio y la etapa de conteo, el tema debe levantar la pierna de su elección aproximadamente 6 pulgadas del suelo, señalaron los dedos, manteniendo las piernas rectas. Mientras mira a los pies elevados, cuenta fuera la carga de la siguiente manera: “mil y una”, “mil y dos”, etc., hasta que dijo a detener. El oficial le indicará el tema para detener después de 30 segundos