This is one of the most widely recognized field sobriety exercises. I refer to this as a sobriety exercise, not a test. I do not refer to it as a test because it is not pass or fail. Furthermore, there is no standardized criteria that results in a grades based upon the performance of the walk the turn. Police officers and prosecutors alike are not allowed to refer to the walk and turn in a courtroom as a test. They can only call it an exercise or a task. Like all the field sobriety exercises, police officers can only testify in a courtroom that a person performed poorly on the field sobriety exercise.
So how does the walk and turn work? How does the walk the line work?
The walk and turn/walk the line is a divided attention task. This means there is a mental and physical component of of the task that occur at the same time. The prosecution will argue that this divided attention task is the important because driving is a divided attention task that requires and mental and a physical component at the same time. They then make the leap that is you perform poorly on the walk and turn then you should not be driving because you would drive poorly because you are under the influence. The mistake that they make is relating that while both driving and the walk and turn are both divided attention tasks they have no bearing on each other. In fact, they could not be more different. If you are like most people you have spent countless hours in the car driving. If you are like most people, you have never performed the walk and turn before. To think that you could perform an exercise nearly very well on the first time is unfair.
What do you do for the walk and turn?
The officer will ask you to stand with your right foot in front of your left foot with your right heel touching your left toe. They will then tell you to remain in that position until they tell you to begin. If you fall out of that position they will hold it against you. When I say fall out of it, I do not actually mean that you call. I mean that you step out of that position with one of your feet. Likewise, the police officer will hold it against you if you begin walking the line before they tell you to begin.
Next the officer will demonstrate walking the line and tell you to take nine heel to toe steps on the line with your hands at your side. At the ninth step they will tell you to take a series of small steps turning around and taking nine more heel to toe steps bad on the line. After these instructions they officer will ask you if you understand the instructions. As soon as you say that you understand the instructions the officer will hold it against you when you do not perform the exercise exactly as it was described to you.
What do the police look for in the walk and turn?
The officers are trained to look to see if you follow the instructions above. This includes taking the correct number of steps, not raising your hands from your sides, making sure your heel is touching your toe on each step, doing the correct turn, and not stepping off the line.
Do the police take into account if you are injured?
The officer is supposed to ask you if you have any injuries. The point of this questions is for the officer to be able to testify that he took your injuries into account during your performance of the walk and turn. The problem with the logic is that the officer is not you and is not a medical professional. There is no possible way for the officer to know if any injury you have or had in the past may affect your performance on the walk and turn. For example, if you have knee surgery, there is no way for the officer to know if you made a full recovery or have a permanent injury from it.
Should you do the walk and turn? Should you refuse to do the walk and turn?
As stated with all field sobriety exercises, you should politely refuse. The walk and turn is designed for the officer to make a decision of whether or not to arrest you. As discussed above the walk and turn is completely subjective with no standardized criteria for grading it. When you are nervous and performing this exercise for the first time on the side of the road in front of a police officer you are bound to make mistakes. Do not give them the opportunity to gather more evidence against you. Especially, when you have done nothing wrong.