In order to be convicted of a DWI/DUI, the prosecutor must prove that either you drove a vehicle while impaired or, regardless of impairment, that you drove a vehicle with a blood alcohol concentration of .08% or higher. There is no requirement of impairment for the second prong. FSTs are evidence of impairment so if the officer has a legal reason to stop your car, the officer’s observation of the smell of alcohol, the physical signs of alcohol consumption and an admission of alcohol consumption constitutes sufficient evidence for arrest regardless of the FST.
In Tennessee v. Silva (3/16/16, Tenn. Ct of Appeal), the court ruled that if the officer smelled alcohol emanating from the car, if defendant had bloodshot and watery eyes and admitted to consuming alcohol, he could be arrested for DWI regardless of the fact that he passed the FST. The rationale was that if there was probable cause for the stop, then the defendant need not display “every known symptom of intoxication in order to support a determination of probable cause.”
Don’t submit to the FST; it is a no win situation. If you pass or fail, you will be arrested if there are observable indicia of alcohol consumption.
Do not assist the officer in the collection of evidence to aid in your own conviction.