Discussion on attacking the one leg stand field sobriety test at a DUI trial

This is Massachusetts DUI lawyer, Michael DelSignore Second blog on field sobriety testing as part of a five part blog series that will be published on this Blog.

The One Leg Stand field sobriety test is the most difficult test given by the police because many people cannot perform this test even if no alcohol is consumed. Accordingly, the idea that failure on this test means someone is under the influence of alcohol is flawed from the start. Even when given under ideal conditions, the test is only 65% reliable according to the studies regarding this exercise. I have attached a link to a field sobriety test student manual used by police officers.

The One Leg stand has the following clues that the officer is suppose to observe:

  • Sways while balancing
  • Using arms for balance
  • Hopping
  • Puts foot down

If a person exhibits two or more clues, that is considered a failure. Though not listed as clues, an experienced Massachusetts OUI attorney will also point out other factors showing good mental ability and coordination.

Like the nine step walk and turn, the one leg stand has an instruction phase. Accordingly, when a person maintains balance during the instruction phase, and starts the test at the appropriate time, those factors showing that the motorist can follow instructions demonstrating, a normal mental ability. Typically, there is no mention of any difficulty maintaining balance during the instruction phase. The idea behind this test is to stress for the jury that the motorist had normal balance other than when required to perform the difficult exercise of balancing on one leg.

While the test requires someone to balance until the count of 30, most jurors probably would consider the test as successfully completed with someone who balances for a much shorter period of time. Further, the inaccuracies of the scoring can be pointed out as typically the officer will not put the details in the report that justified the conclusion. One of the clues on the one leg stand is that a person cannot use their arms for balance; however, the training of the officer states that the arms have to be more than six inches from the body. In many cases the details of how someone performed are missing from the police report.

If you read your police report and see that the officer found you failed the one leg stand, your case can still be won. In almost all cases, the police will claim that a motorist failed field sobriety tests. The one leg stand is the most difficult exercise to perform; even the police training manual, states that some people cannot perform the test, including someone over 50 pounds overweight or over the age of 65. As a result, the officer would have to admit that the test is easier for someone younger and in shape, then for someone older, who has been working throughout their life and may have physical injuries. In fact, the early versions of the police training manual stated that some people could not perform the one leg stand test even without consuming any alcohol; this language has since been removed from the manual.

Techniques to minimize the one leg stand at trial:

  • Point out that the motorist had no trouble with balance when on two feet, listening to the instruction to the one leg stand, no trouble with balance getting out of the car, did not stumble when walking on the nine step walk and turn, and had no difficulty with balance during booking.
  • Stress that this is a physical fitness test and is one size fits all, the officer gives the same test to a college student as a carpenter who has spent years working doing manual labor. The older person, with physical aliments, is disadvantaged from the start.
  • underscore that even the Government study indicates that the test is only 65% reliable, under perfect conditions. A 35% failure rate should raise a reasonable doubt.


As a dedicated Massachusetts OUI attorney, I have spent a considerable amount of time discussing field sobriety testing with other DUI lawyers around the country, reviewing the police training manual and developing and revising cross examination questions to better point out for the jury on the unfairness of these exercises, the lack of reliability and careless description by police officers of how a motorist actually performed on the exercise. You can schedule an appointment immediately by calling 781-686-5924 or 508-455-4755 to set up a free consultation. At that appointment, I can explain to you my experience and review your cases and defenses. You may also send an email through this website.

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