Challenging the Accuracy of Field Sobriety Tests

PoliceApart from the subjective judgment of the police officer, a Field Sobriety Test or FST determines how badly impaired a driver is and consequently, what traffic offense the driver committed. Naturally, the importance of this test demands a challenge, or at least questions regarding accuracy.

There are many factors at play here: the police officer’s judgment, his testimony, the contents of the police report and results of the FST. A person’s performance on an FST could mean the difference between being let go and having to consult with local drunk driving attorney in Houston.

Are You Drunk or Are You Drunk?

In theory, police officers should be good at judging the result of these tests. When a person fails the FST, the general assumption is that the person was certainly very drunk. This, of course, is understandable because it should be easy to tell whether a person is drunk or not.

Unfortunately, this is not always the case. The lack of scientific basis aside, most FSTs are hardly precise. A study conducted by Dr. Spurgeon Cole gathered 14 police officers who viewed 21 subjects taking FSTs. The officers were then asked to decide who had too much to drink and should not drive.

Chink in the Armor

Results revealed that officers determined 46% of the subjects to be legally intoxicated. The kicker in all of this is that none of them were. All the subjects had a blood alcohol level of 0.00%–sober as sober can get. Not only were the results unsettling, they also exposed a very vulnerable chink in the police force’s armor.

It could be due to the lack of training or a slip in judgment, but what about the scientific backing of Field Sobriety Tests? When these tests were still on their way to being standardized, roughly 30% of subjects who were falsely arrested.

This was in 1981. Several studies and lots of refining after, there are claims that the Field Sobriety Tests used by modern police forces are able to achieve a 91% success rate—or so they say.