Field Sobriety Test Evidence

Law enforcement officers are taught to gather, as additional evidence of alcohol impairment, any mistakes or cues they are able to find on three standardized field sobriety tests. Standardized means officers are taught to administer each of three standardized tests the same way to subjects
every time the tests are administered.

The three tests, according to the National Highway Traffic Safety Administration (NHTSA) training manual are the horizontal gaze nystagmus or HGN test, the Walk and Turn or W/T test; and the One Leg Stand or OLS test.

During the Horizontal Gaze Nystagmus test, the officers are taught to determine whether you are an appropriate medical candidate fro the test, then instruct you to follow a stimulus, such as a pen, with your eyes, while the officer looks for a slight jerking movement of the eyeballs while
your eyes are following, or attempting to follow, the stimulus; distinct jerking movements at the farthest point the pen or other object is held out; and jerking movement in the eyes prior to an angle that is closer to a forward eye position or gaze.

During the Walk and Turn test, you receive a barrage of instructions, are given no opportunity to practice and, in many cases, asked to walk on an 'imaginary' line in the dark, of unknown or undisclosed width, taking nine heel to toe steps up, pivot, then take nine heel to toe steps back on the same imaginary or invisible line. The officers are taught to write up as 'mistakes,' or cues starting before being told; not keeping balance during instructions; stepping 'off' the imaginary
or invisible line; missing heel to toe; natural use of your arms to maintain your balance; taking an improper number of steps; or making an improper turn without the 'pivot.'

During the One Leg Stand Test, you receive more instructions and, again, no opportunity to practice. You are instructed to raise one leg six inches off the ground, while counting 'one thousand one, one thousand two. . . ' and so on, until you are told to stop. The officers are taught to write up as 'mistakes' or 'cues' any of the following; 'excessive' sway while balancing on your one leg; natural use or raising your arms, to maintain your balance on one foot; putting
your foot down; and hopping.

In order for test results for any of these 'standardized' tests to be 'valid,' however, the National Highway Traffic Safety Administration (NHTSA) Manual states that each test must be administered in the prescribed, standardized manner. No field sobriety 'test' other than these three tests, whether picking up a coin; touching finger to nose; counting backwards by numbers or alphabet, as part of Rhomberg- Modified test, etc. has ever been 'validated' by research or clinical trials to be able to predict possible alcohol impairment.

Jeffrey Siirtola is a trained NHTSA/IACP field sobriety test administrator / practitioner. If the officer did not properly administer your tests, vigorous challenges to this part of the evidence against you, along with challenges to other parts of the evidence developed in your case, may result in acquittal, dismissal, or reduced charges for legal reasons, in your particular case.