The heel-to-toe walk test, which is also known as the, is the third field sobriety test in the three-test National Highway Traffic Safety Administration-approved three test battery. It's a divided attention test which measures both mental acuity and physical dexterity. Scientifically, intoxicated people are basically unable to multitask in this way.
In terms of scientific literature in support of the WAT, that's about it. There is simply very little evidence that this venerable test accurately determines sobriety or intoxication.
Much like the other two FSTs, administering officers look for clues of. Some of them include:
· Failure to stand heel-to-toe during the instructions,
· Starting before the officer says "start,"
· Beginning with the wrong foot,
· Failure to walk heel to toe,
· Extending arms for balance,
· Incorrect number of steps,
· Stumbling, and
· Ending the test before the officer says "stop."
There are a lot of possible clues here. Moreover, the "failure to walk HTT" clue is per step. If the defendant takes thirty steps, that's thirty potential intoxication clues.
Typically, if the defendant exhibits more than four clues, the officer will testify that the defendant "failed" the test. Most officers judge very harshly. The slightest misstep is a clue. Fortunately, the jury has the final say-so as to whether the defendant "passed" or "failed" the test.
Problems with the WAT
Test subjects begin at a disadvantage. The WAT instructions are longer than any of the other tests. During all this time, the defendant must stand uncomfortably in a heel-to-toe position. So, by the time the test starts in earnest, they are already fatigued.
Furthermore, given the extensive number of potential clues, the test is basically designed to make people fail.
Finally, and perhaps most importantly, most police officers make absolutely no allowances in the WAT or any other field sobriety test.
Officers are supposed to ask defendants if they suffer from any mobility impairments, dementia, or other condition which may affect their performance. But terms like "impairment" and "disability" are incredibly vague. There is simply no way of determining the extent of impairment. Additionally, there is no "normal" baseline. Some people have inner ear or other conditions, so they have naturally poor balance. Their "normal" performance may have several clues.
Test conditions matter as well. A defendant who walks an imaginary line in the dark while wearing flip-flops will not perform as well as someone who walks an actual line in a well-lit room while wearing sneakers. Yet officers expect them both to do the same things. That's not realistically possible.
The approved field sobriety tests are weak evidence of intoxication, at best. For a free consultation with an , contact Herreth Law. After-hours appointments are available.