Field Sobriety Testing

Why Field Sobriety Tests Are Poor Indicators of Impairment

Even though field sobriety tests usually involve both mental and physical challenges, they are not valid indicators of whether a person is impaired by alcohol or some other substance. Even the main researcher of standardized field sobriety tests, Marcelline Burns, has testified as to this fact.

Field sobriety tests are given in a “one size fits all” manner. The same field sobriety tests that are given to teenagers are given to older adults, and the same tests that are given to athletes are given to those who are in poor physical condition. Not only are the same tests given, but the test-takers are judged against the exact same standard. Common sense tells us that this is neither a fair nor an accurate approach. Advanced age, obesity, back or joint injuries, or other medical conditions, can render field sobriety tests virtually useless as indicators of impairment. Some people are simply uncoordinated. Some people get so scared that small motor skill function is greatly diminished.

Another problem with field sobriety tests is that they are usually given in a less than ideal environment, often a noisy or poorly lit roadside. Imagine if you had to take a college final under these conditions! Often the ground is not level or there may be cracks or gravel in the area of the test. A recent rain can make the surface slippery. Strong winds can make balancing in the awkward test positions even more difficult. High heels can make balancing more difficult. Cold weather can also increase the difficulty of these tests.

In addition, the natural reaction for a person who is being accused by a police officer of driving under the influence is to become extremely nervous. Being in this heightened state of anxiety makes it difficult to concentrate and perform well on field sobriety tests. This can lead police officers to falsely determine that a person is under the influence.

“Field sobriety tests” are tests that police administer, usually on the roadside when an officer suspects a person of driving under the influence. These tests are supposed to allow the officer to make a better determination about whether the person is legally intoxicated. We will discuss some of the most common field sobriety tests as well as factors that often make field sobriety tests poor indicators of whether a person is actually intoxicated.

Horizontal Gaze Nystagmus Test

This test is commonly referred to as the “HGN” test for short. It involves an officer having a person follow a finger or pen with their eyes as the officer moves the finger or pen from side to side. Horizontal Gaze Nystagmus is a horizontal jerking that occurs when a person looks to the side with his or her eye. Alcohol and certain other substances can impede the brain’s ability to precisely control the muscles of the eye. As a person’s level of alcohol intoxication goes up, the degree of this horizontal jerking of the eye can become more pronounced. When the officer conducts the HGN test, he is looking for this horizontal jerking motion. One of the problems with the HGN test is that the police officers performing it often lack the expertise to properly perform and evaluate the test. Another problem with the HGN test is that it is not “alcohol specific.” In other words, there are substances , medications, and health problems that have nothing to do with alcohol intoxication that can cause HGN. Some people have this nystagmus present all the time.

Walk and Turn Test

In this test the person must walk heel to toe along a real or imaginary line for nine steps then turn and take nine heel-to-toe steps back to their starting point. The test has two stages: (1) the Instruction Stage and (2) the Walking Stage.

During the instruction stage the person is supposed to stand with their feet in a heel-to-toe position and keep their arms by their sides while listening to the officer give instructions for the walking stage.

During the walking stage the person is supposed to take nine heel-to-toe steps, turn by taking a series of small steps with one foot while keeping the other foot on the line, then take a second nine heel-to-toe steps back along the line. Throughout the test the person is supposed to keep their arms down by their sides. According to “police” jargon, there are different “clues” the officers look for during the test that are supposed to be indicators of intoxication, including:

One Leg Stand Test

The person taking the test is instructed to stand with one foot approximately six inches off the ground and count aloud by thousands (One thousand-one, one thousand-two, etc.) until told to put the foot down. The officer times the subject for 30 seconds. The officer looks for four indicators (prior to 30 seconds):

ABCs Test

The test-taker is asked to stand with their feet together, arms to their side, head back, and their eyes closed. While standing in this position, they are supposed to say the alphabet (either from A to Z or a portion of the alphabet) without singing it. The officer observes to determine if the person is swaying and whether the alphabet was said correctly.

Count Backwards Test

The test-taker is asked to stand with their feet together, arms to their side, head back, and their eyes closed. While standing in this position, they are supposed to recite certain numbers backwards, for example, from 71 to 53. The officer observes to determine if the person sways and whether the sequence of numbers was said correctly.

Finger Count Test

The test-taker is asked to hold their hand out palm up and to touch their thumb to each of the tips of their fingers. The officer will either ask that the person start with the index finger or the pinky finger and touch each finger tip in sequence, counting out loud “one, two, three, four, four three, two, one, one two, three, four, four, three, two, one.” The officer observes to determine if the person touches the finger tips in the correct sequence and counts correctly.

Finger to Nose Test

The test-taker is asked to stand with their feet together, head back, eyes closed and with their arms extended out at shoulder level to each side and when the officer commands, saying either left or right, the test-taker must touch the tip of his finger to the tip of his nose. Most police officers will ask that the person should move his selected arm forward, roll the palm of the hand upwards, then bring the arm in and touch the tip of the finger to the nose. The officer is looking to see if the person is able to follow the instructions and if the person sways during the test.