What Does Not Work: Performing the “Nine Step Walk and Turn” test on tip-toe, with several twirls thrown in, while singing ”Fiddler on the Roof” songs in your best falsetto voice as proof that you were not driving under the influence of anything stronger than show tunes.

What Works: If a law enforcement officer pulls you over on suspicion of driving under the influence of alcohol (DUI), be cooperative—but also be aware of your legal rights. In Utah, there are three tests that can be used to determine DUI:

• Standard field sobriety tests (SFSTs) to measure physical responses such as balance, attention, and eye movements
• Portable breath test (PBT) that gives a general assessment of alcohol in the breath
• Blood alcohol content (BAC), measured by a breath test machine

SFST and PBT results are notoriously inaccurate and you have the right to refuse either. You are not obligated to explain the reasons for your refusal. In fact, the less you say, the better. However, make sure you remain polite and cooperative.

An officer who believes you are intoxicated, even without on-the-spot test results, can arrest you and ask you to come to the police station for a breath test. You do not have the right to refuse this request. The penalty for doing so could be an 18-month suspension of your drivers license.

SFST and PBT evidence is not admissible in court, so most DUI cases hinge on the BAC. In our attorneys’ experience, mistakes in obtaining or processing DUI evidence can cast doubt on the accuracy of a BAC reading.