Field sobriety tests (FSTs) are tests conducted by police officers on those whom the police suspect of driving under the influence of drugs or alcohol. These tests do not rely on any sort of special equipment, cannot determine the exact amount of drugs or alcohol in the system, and depend entirely on the subjective observations of the police officer or investigator performing the tests. Perhaps the biggest problem with these tests is the fact that these tests rely on the subjective observations of police officers, which is to say, the officer’s opinion.

An Opinion is Not Evidence

Considering that a person suspected of driving under the influence is at risk of losing his or her very freedom, the problem with depending on a police officer’s opinions about FSTs should be obvious – how can a suspect of driving under the influence be given as fair a trail as possible when an observation by one officer may differ from the observation of another?

Common FSTs include the walk and turn test, the finger to nose test, and the horizontal gaze nystagmus test. When a police officer administers these tests, he or she will make observations as to how the person performs and will annotate these observations via a police report. For example, the walk and turn test requires the suspect to walk heel to toe, on a straight line, for a predetermined number of steps before turning around and walking back, heel to toe, to the starting point.

Since the test is subjective, it is entirely possible for 10 different police officers to observe the same test and come up with 10 very different results. Some might say the suspect failed to walk heel to toe for every step, while others might say that it appeared that the suspect failed to stay entirely on the straight line for the whole test.

So, instead of leaving their very freedom in the hands of a single police officer whose single opinion may or may not be an accurate depiction of the amount of drugs or alcohol in the system, suspects of driving under the influence are encouraged to refuse to perform any and all FSTs.

Refusing FSTs

Contrary to popular belief, suspects of driving under the influence charges in California are always allowed to refuse to perform field sobriety tests. Granted, this will most likely result in a further detention, but at least it will keep the prosecutor from being able to present the results of a field sobriety test as evidence in a trial. Instead of submitting to FSTs, which includes portable breath tests, individuals suspected of DUI should demand that their blood be tested.

California’s implied consent laws can make it a crime for a person to refuse chemical testing, which include blood, breath or urine tests, but it is not a crime to refuse FSTs that require the suspect to walk a straight line, touch the finger to the nose, or blow into a portable breath machine on the side of the road.

The law allows suspects of DUI the chance to choose the type of chemical test that they will submit to, with options usually being blood, breath or urine. When available, suspects are advised to submit to a blood test, because blood testing is the most accurate type of chemical test available and it creates a sample which can then be preserved and independently tested by the suspect’s own legal counsel.