A DUI arrest can be confusing when a driver believes they were not impaired. In Tennessee, DUI law covers driving under the influence of alcohol, marijuana, controlled substances, drugs or other substances that impair the ability to safely operate a vehicle. A breath test showing no alcohol does not necessarily end a DUI investigation.
How can a DUI arrest happen with a .00% BAC?
A breath test measures alcohol, but it does not determine whether someone is affected by drugs or other substances. During a traffic stop, an officer may also consider the way a person was driving, statements made during the encounter, physical signs and performance on field sobriety tests.
Tennessee’s DUI law also covers impairment involving drugs and other substances. As a result, a .00% breath test does not by itself eliminate the possibility of a DUI charge.
What role could oral fluid testing play?
Tennessee law allows law enforcement officers to request oral-fluid testing in certain DUI investigations. Under T.C.A. § 55-10-406, an oral-fluid test may be administered when:
- The driver consents to the test
- A search warrant authorizes the test
- The test is conducted incident to a lawful arrest for DUI or another qualifying offense under Tennessee law
- Exigent circumstances allow the test without the driver’s consent
A lawfully administered oral-fluid test result may be admitted as evidence at trial.
The result is only one part of the case. The officer’s observations, circumstances of the encounter and other evidence may also affect how prosecutors evaluate the allegations.
What should you do after a DUI arrest?
Write down everything you remember about the traffic stop while the details are fresh. Keep records of prescription medications, medical conditions and anything else that could help explain what happened. Save paperwork, test results and other documents related to the case.
If later testing does not support the state’s claim of impairment, that evidence could become important to the defense. It does not automatically resolve the case because prosecutors may rely on other evidence from the stop.
A DUI charge based on suspected drug impairment often depends on more than what a breath test shows. The testing method used, the officer’s observations and the circumstances of the stop can all affect how the evidence is evaluated and what options may be available.
