Legal experts argue that field sobriety tests can be inaccurate

Legal experts argue that field sobriety tests can be inaccurate

We have previously written that Wisconsin police must ask a driver to submit to a field sobriety test in order to determine if there is probable cause for a DUI arrest or for more extensive blood-alcohol-concentration tests.

But how that test is administered is important, as it can greatly affect the suspect’s performance. Furthermore, legal experts say that field sobriety tests themselves may be out of date and difficult to perform, even by sober individuals.

A DUI defense attorney in California says: “These tests originated 30 years ago, and as we’re not in the same shape we were in 30 years ago, there has not been any research as to how regular people perform these (tests).”

Many of the commonly used tests are measures of balance and dexterity. For instance, a suspect may be asked to walk a straight line as if walking along a tightrope. Some suspects are asked to lift up one foot and count.

But critics of these tests say that they do not actually tell an officer whether a suspect has been drinking, nor are they any reflection of a person’s driving ability. They only seem to measure a person’s balance and motor skills, which could be impaired by any number of factors besides alcohol, including age, weight or a pre-existing medical condition.

The same DUI defense attorney mentioned above recently taught a news reporter how to administer two common field sobriety tests. Then, several sober passersby agreed to submit to the tests. Most admitted it was physically harder than they thought it would be.

And that was during a no-pressure situation. Imagine that you were asked to take the test on the side of a Wisconsin highway on a cold wintry night, and that your very freedom was at stake. It might be substantially harder to pass.

To be clear, the field sobriety test is just the first step necessary in a DUI charge and conviction. However, it is important to remember that the test is meant to establish whether a suspect can be subjected to more testing and possibly arrest.

If the test is not a good indicator of alcohol impairment, does it actually establish probable cause?

Source:, “Field sobriety tests may not always be accurate,” Oct. 27, 2011