This is usually the second test an officer will conduct on an individual they suspect of a DUI. What law enforcement is looking for is the person’s ability to listen to complicated instructions and then follow the instructions while performing the tasks. This test has two phases, both of which the officer is looking for “clues” of impairment. If an individual receives two or more clues during the test, then they have “failed” the test. The phases of the test and what the officer is looking to “clue” a suspect for are listed below:

Instructional Phase:

What the officer is supposed to do: The following instructions and demonstrations are what the officer should give to the individual about to perform the test. The officer is supposed to tell the person to:

  1. Imagine a straight line;
  2. Put your right foot on the line in front of your left foot, with the toe of your left foot touching the heel of your right foot;
  3. Put your arms by your sides
  4. Keep this position “instructional position” until the officer has finished the instructions. Don’t start to perform the test until told to do so;
  5. As the individual if they comprehend the instructions to this point;
  6. Wait until the individual states they understand the instructions
  7. Tell the individual when the cop tells them to start they are to take nine heel to toe steps on the line, then use a series of small steps with their other foot to turn around (officer should demonstrate this) and then take nine heel to toe steps back along the original line;
  8. The officer should instruct the individual that while they are completing the tests, they are to keep their arms at their sides, watch the feet for the entire time, and count the steps aloud;
  9. The officer should inform the individual that once they start the tests, they should not stop until it is completed;
  10. The officer should then ask if the individual understands the instructions.

What the suspect is supposed to do: During the instructional phase is when you can ask the officer questions. There are three things an individual should be aware of; 1) be sure to comprehend the officer’s instructions, 2) maintain balance, and 3) only begin the test once the officer instructs you to do so.

What clues the officer is looking for: an officer can only clue an individual for two things during this phase; 1) prematurely starting the test and 2) failing to keep their balance.

Common mistakes officers make:

Interpretation: Police will sometimes forget that the field sobriety test “clues” are required to be evaluated in context. Just because an individual doesn’t technically perform the test perfectly, that doesn’t mean they are intoxicated. Although some “clues” are showcased, they could have another explanation. If another explanation for the suspect’s behavior is obvious, and an officer still strictly applies the field sobriety test standards, that officer can lose their credibility. “This test is not a pass/fail test, it is only for the officer to see signs of impairment.” (2013 Participant Manual Session 8, Page 46 of 62)

Timing: The instructional phase should only last about 40 seconds. Law enforcement often forget that the suspect is in the “instructional position” with their right foot in front of their left. Every second the officer extends this phase just makes it more likely that the individual will fall out of position and then they will be clued for that action.

Improperly scoring a “failure to maintain balance while listening to the instructions.” Clue: Frequently a person will shift their weight, wiggle, or something similar while in the instructional position. It is common sense that people will make some type of movement while in a certain position for an extended time period. The test permits some movement during this phase. Officers sometimes completely remove the ability to move during the test. They will then give an incorrect clue of “failure to maintain balance while in the instructional phase” as they claim any sort of movement is a failure to maintain balance. Law enforcement forgets that NHTSA manual on the standard field sobriety tests mandates than an officer can only validly clue the individual if they “break stance,” a slight movement of the arms to keep their balance or some swaying back and forth does not qualify as a clue. (2013 Participant Manual Session 8, Page 44 of 62)

Improperly scoring a clue for “beginning the test too early”: Generally, this happens when an officer doesn’t tell the individual to not start the test until told to so or if the officer didn’t ask the individual if they understood all of the instructions. If an officer fails to do either of those two things, they cannot validly clue someone for prematurely starting the test.

Test Interpretation Phase:

What officer is supposed to do: They are to observe the person only. They are not allowed to give additional instructions or correct them by any means. They are supposed to use a common-sense approach in applying the NHTSA manual’s standards to determine if the person is intoxicated.

What the suspect is supposed to do: This is quite difficult. A suspect has to remember all of the instructions and perform the requested tasks. This is in addition to the added pressure of being in a stressful situation in an unfamiliar location.

What the officer is looking for:

Whether the suspect touched heel to toe: there is a permitted range of ½ inch. Therefore, if the feet do not actually touch, they can’t be farther apart than ½ inch. (2013 Participant Manual Session 8, Page 45 of 62)

Whether the individual stepped off the line: In order for the clue to be valid, the entire foot has to be off the line. (2013 Participant Manual Session 8, Page 45 of 62)

Whether suspect used arms to balance: They can only be clued if they meet the standard. The standard is that the arms must be raised more than 6 inches away from the body. (2013 Participant Manual Session 8, Page 45 of 62)

Whether suspect makes an improper turn: A clue is only given if the individual removed their foot from the line during the turn, if they didn’t perform the turn as told to do so, or if they lose balance during the turn. (and incorrect turn is to spin or pivot) (2013 Participant Manual Session 8, Page 45 of 62)

Whether suspect takes incorrect number of steps: If the person takes the incorrect number of steps in any direction, it is a valid clue. (2013 Participant Manual Session 8, Page 45 of 62)

Common mistakes officers make:

Test conditions: The test should be performed on a reasonably dry, hard, level, non-slippery surface. There needs to be sufficient room to perform the tests as well. (2013 Participant Manual Session 8, Page 41 of 62). It is not following the NHTSA guidelines if the officer requests the individual to perform the test in a location that doesn’t meet these standards.

Suspect’s age: A suspect over the age of 65 will have trouble with this test regardless if they consumed alcohol or not. (2013 Participant Manual Session 8, Page 41 of 62). Officers should not conduct the SFSTs to a person over 65 years of age.

Suspect’s physical condition: If a person has leg, back, or inner ear problems, they will have difficulty on this test regardless if they have consumed alcohol or not. (2013 Participant Manual Session 8, Page 41 of 62). The test should not be conducted on a person with these physical problems.

Suspect’s footwear: If an individual has on heels greater than 2 inches, they should be given the change to take the shoes off to perform the test. (2013 Participant Manual Session 8, Page 41 of 62) If the officer fails to grant the individual this opportunity, they are then operating outside the NHTSA guidelines.

Clue suspect for not counting steps aloud: Although “counting aloud each step” is an instruction, failing to do so is not a valid clue. (2013 Participant Manual Session 8, page 43 of 62) Often officers will do this mistakenly.

Clue suspect for not watching their feet: Although “keep watching your feet” is an instruction, failing to do so is not a valid clue. (2013 Participant Manual Session 8, Page 43 of 62). Often officers will do this mistakenly.

Giving instruction during the Performance phase of the test: Officers tend to forget the most important part of the Standard Field Sobriety Tests and that is that the tests are standardized. This means that each test must be given in the same way if they intend to rely on their results. An officer is not permitted to instruct an individual who is performing the tests. An example would be, the officer cannot remind the suspect to count aloud if they have failed to do so. This additional instruction introduces another stimulus to the test and thus makes it more difficult and as a result, invalidates the test.

Problems with the walk and turn test

Officer Mistakes: As seen above, there is ample opportunity for the officer to make a mistake in either scoring the test or giving the instructions. These are two most common mistakes that are made on any of the SFSTs and result in people being falsely accused of a DUI.

Reliability: There is one data point and four studies which back up the Walk and Turn Test.

Data Point: the NHTSA Participant Manual cites “recent research” which indicates a 79% accuracy for this test. (2013 Participant Manual Session 8, Page 47 of 62)

Southern California Research Institute Study: This was the original research done which resulted in the SFST curriculum and it stated that this test had a 68% accuracy of detecting those at or above a .10 BAC. This study detects an alcohol concentration higher than the limit, is over 40 years old, and has a terrible accuracy rating. (This study is not available online)

Validation of SFST at BAC below 0.10 (San Diego Study): This study was in 1998, had a sample size of 297 motorists, and claims a 79% accuracy rate for arrests based on this test.

A Colorado Validation Study of the SFST Battery: This study was in 1995, had a sample size of 305 individuals, and claims an 86% accuracy when all three tests are administered.

A Florida Validation Study of the SFST Battery: This study was in 1997, had a sample size of 256 breath tests, and claims a 95% accuracy when all three tests are administered.