DUI Field Sobriety Tests:
The Walk and Turn Test and One Leg Stand Test
During a traffic stop for suspicion of DUI, law enforcement may conduct one or both of these Standard Field Sobriety Tests (SFSTs).
Walk And Turn Test
The walk and turn test is a divided attention test with two stages: (1) the instruction stage and (2) the walking stage.
During the instruction stage drivers must stand with their feet in a heel-to-toe position, keep their arms to their sides, and listen to instructions. This requires drivers to divide their attention between balancing and processing information. If drivers have trouble following instructions that can be used as evidence of impairment.
During the walking stage drivers must take nine heel-to-toe steps, turn in the prescribed manner, and take nine heel-to-toe steps back. Drivers must count their steps out loud while watching their feet. Drivers must also turn by keeping their front foot on the line and use their other foot to take several small steps to complete the turn. This requires drivers to divide their attention between balancing, counting out loud, and using short term memory to recall the number of steps and turning instruction. Any problems performing these tests can be seen as evidence of impairment, although there may be perfectly innocent explanations for the difficulties, such as arthritis or lack of sleep.
The officer will look for a total of eight clues: (1) failing to balance during instructions; (2) starting too soon; (3) stopping while walking; (4) failing to touch heel-to-toe; (5) stepping off the line; (6) using arms to balance; (7) losing balance on the turn or turning incorrectly; and (8) taking the wrong number of steps. According to research conducted by the National Highway Traffic Safety Administration (NHTSA) two or more clues has correlation with a blood alcohol concentration of .10 or more. NHTSA believes the walk and turn test is 68% accurate. However, the NHTSA studies have not been fully peer reviewed. Which means, essentially, that they are not validly scientific.
The officer should not be permitted to claim that two or more clues means the driver has a blood alcohol concentration of .10 or more pursuant to the same principles set forth in Baity. The test can also be attacked. The driver is not informed about what exactly he or she is being tested on or what the officer is specifically watching for. Officers may also use a line that is either real or imaginary. Not walking on an imaginary line is hard to evaluate since the line does not exist. You literally have to be a mind reader to pass this test.
Things other than alcohol may affect coordination. The officer’s instructions may also be inaccurate. The officer’s observations may be inaccurate. A given individual’s coordination or athletic ability may have little bearing on the amount of alcohol or THC consumed. Expert testimony may also undermine the weight that should be given to the test performance. A knowledgeable DUI attorney may also show how a driver actually performed well on the test from an objective point of view.
One Leg Stand Test
The one leg stand test is another divided attention test that consists of two stages: (1) the instruction stage and (2) the balance and counting stage.
During the instruction stage drivers must stand with their feet together, keep arms at their sides, and listen to instructions. This divides the driver’s attention between balancing and processing the instructions. As with the ‘walk and turn test’, failure to follow or understand instructions can be used as evidence of impairment.
During the balance and counting stage, drivers must raise one leg with their foot approximately six inches off the ground and keep their foot parallel to the ground. While looking at the raised foot, drivers must count “one thousand and one,” “one thousand and two,” “one thousand and three” until told to stop. This divides the driver’s attention between balancing and counting out loud.
NHTSA believes impaired drivers are able to stand on one leg for up to 25 seconds but cannot do so for 30 seconds. Officers are trained to look for four clues: (1) swaying while balancing; (2) using arms for balance; (3) hopping; and (4) putting the raised foot down. According to research conducted by NHTSA two or more clues has correlation with a blood alcohol concentration of .10 or more. NHTSA believes the one leg stand test is 65% accurate. Again, the NHTSA studies have not been fully peer reviewed, meaning they are not really scientifically acceptable.
The officer should not be permitted to claim that two or more clues means the driver has a blood alcohol concentration of .10 or more pursuant to the same principles set forth in Baity. The tests can also be attacked. Again, the driver is not informed about what he or she is specifically being tested on. Reasons other than drugs and alcohol may affect one’s ability to perform this test. Anyone over the age of 50 understands this, especially when it comes to standing on one leg. It’s not as easy to do this type of thing as it used to be.
Our job is to explain these things to prosecutors, judges, and, ultimately, jurors.
The officer’s instructions may also be inaccurate. The officer’s observations may be inaccurate as well. A given individual’s coordination or athletic ability may have little bearing on the amount of alcohol or THC consumed. Expert testimony may also undermine the weight that should be given to the test performance. As mentioned above, a knowledgeable DUI attorney may also be able to cross examine the officer to show the jury how their client’s performance on the test was actually good from an objective point of view.
Contact the DUI defense attorneys at Platt, Thompson and Buescher today to talk about resolving your DUI charge. We serve Oak Harbor, Island County, Bellingham, Burlington, Mt. Vernon, Whatcom County, Skagit County, Seattle, King County, and greater western Washington. Call 360-474-3994 or use the online form.