In our last post, we began discussing the issue of field sobriety testing. As we noted, the Standard Field Sobriety Test consists of several discrete tests. It is important for readers to understand that they do not have to submit to field sobriety testing, and it usually in their interests not to do so, since officers essentially get to decide whether they think you passed or failed and this judgment can be inaccurate.

Technically, field sobriety tests may only be required when an officer has probable cause to make an arrest for drunk driving. Prior to that, submission to a field sobriety test is voluntary. Officers will not tell you this, though. They’ll just ask for the test. Also, DUI suspects should not expect an officer to read them their Miranda rights prior to requesting a field sobriety test. They’ll only do that once an arrest has been made, relying on the suspect’s ignorance of his or her rights and willingness to comply.

With respect to refusal, the fact that a defendant refuses to submit to field sobriety testing is not admissible in court to prove his or her guilt. The same is true of refusing preliminary breath testing. That being said, field sobriety testing to which a suspect voluntarily submits may be admissible in court to establish intoxication.

The results of field sobriety tests are only admissible in court, though, if the test is performed properly by a trained officer. The standards according to which these tests must be performed vary from state to state. In order for prosecutors to use evidence of field sobriety tests at trial, they need to lay the proper foundation for the reliability of the test. This is an important point when building a defense case in which field sobriety testing is an issue. The question is: was the test performed correctly, and is there sufficient proof of this?

Those who face DUI charges should always work with an experienced attorney to ensure their rights are protected. Our firm is committed to making sure DUI defendants have the strongest case possible.


C.R.S. 42-4-1301 (2014).

American Prosecutors Research Institute, “Admissibility of Horizontal Gaze Nystagmus Evidence,” May 2003.

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