Drivers who are pulled over in Minnesota on suspicion of drunk driving will likely be asked to complete the standardized field sobriety tests, which are three divided-attention tests that are performed at the roadside. Unlike breathalyzers, these tests are not mandatory, meaning that drivers have the right to refuse them. Police officers use the SFSTs to help them to obtain enough probable cause to make arrests and to gather observations about the drivers that can be used against them in court. A DWI attorney advises people to politely refuse the SFSTs because they are designed in such a way that most people fail them. The tests were standardized by the National Highway Traffic Safety Administration and have been used by law enforcement officers for several decades.
Horizontal Gaze Nystagmus
In the horizontal gaze nystagmus test, officers use a stimulus that the drivers are supposed to track with their eyes from left to right. The officers will be watching for nystagmus, which is an involuntary jerking movement of the eyes. If the nystagmus begins prior to a 45-degree angle, officers take this as a sign that the drivers might be under the influence of alcohol. The problem with this test is that more than 40 conditions can cause nystagmus other than ingesting alcohol.
Walk and Turn
In the walk-and-turn test, the officers ask the drivers to take nine heel-to-toe steps down a straight line before swiveling around on one foot and taking nine heel-to-toe steps straight back down the line. If the tests are performed on the road side, the line will likely be an imaginary one. The officers look for the drivers to make mistakes on each step, such as double-stepping, failing to stay on the line, not turning on one foot and etc. Because it is possible to make several different mistakes with each individual step, the potential for failing this test is high.
One Leg Stand
The one leg stand test involves the officers asking the drivers to stand with one leg raised six inches off of the ground while counting to 30 by thousands, which should be around 30 seconds. Officers watch for people to balance with their arms, sway, hop or put their foot down early. Many people fail this test despite being sober. A DWI attorney may review how the tests were performed and any video in order to challenge them. Since they are optional, drivers should not take them.