Chemical Testing

Many people arrested for driving under the influence (DUI) in Tennessee have taken a breathalyzer or other chemical test indicating that their blood alcohol concentration (BAC) level was over the legal limit. The chemical test results are often an important part of the prosecution’s case against a defendant facing a DUI charge in Davidson or Williamson County. Nashville DUI lawyer Bernie McEvoy understands that chemical testing may be unreliable, however, and he can investigate factors that may affect the accuracy of a breath or blood test. Attorney McEvoy has the experience to contest chemical test results when appropriate as well as protect your rights during the proceedings, whether this is a first or subsequent DUI.

Driving under the influence of alcohol or drugs is a criminal offense. A person may be charged with a DUI in Tennessee if a breath or blood test indicates a BAC level of .08 percent or more, or .02 percent or more for an underage driver. In most DUI cases, a police officer initiates a traffic stop. If the officer believes that you are driving while under the influence, the officer may ask that you take a breath or blood test for the purpose of determining the alcohol or drug content of your blood. In Tennessee, a driver is deemed to have given implicit consent to a breath test by virtue of operating a motor vehicle in the state. While a driver may refuse to take a breath test, he or she may be subject to penalties for the refusal.

Under Tennessee law, a police officer may administer a breath test with the driver’s express consent, upon an arrest for a DUI or related offense, pursuant to a search warrant, or with the driver’s implied consent by operating a motor vehicle in Tennessee. Furthermore, a breath test is required when the police officer has probable cause to believe that the driver committed a DUI or related offense, such as vehicular assault or vehicular homicide, and one of the following circumstances applies: an accident occurred, a child under the age of 16 was in the car, or the driver has a prior DUI conviction. Refusing to submit to a breath test when required as described in the above circumstances or pursuant to a search warrant is a Class A misdemeanor.

A blood test may only be administered if there is probable cause that the driver was under the influence of drugs or alcohol or committed a related offense, and the driver consents and executes a waiver, police obtain a search warrant, or exigent circumstances allow an exception to the warrant requirement. Significantly, the implied consent given by virtue of operating a vehicle in Tennessee does not apply to blood testing. Nor can blood be taken from an unconscious or incapacitated person for testing purposes without a search warrant or exigent circumstances. Refusing or obstructing a blood test pursuant to a search warrant, however, is a criminal offense.

Appropriate defenses against chemical testing in a DUI case will depend on the facts. In some situations, the defense may argue that the test results cannot be admitted into evidence because of police misconduct or a constitutional violation. If the results are admissible, the defense may present witnesses or evidence to cast doubt on the reliability of the test. A thorough defense attorney will also investigate whether the test was administered properly, whether the blood sample was stored, transported, and tested according to protocols, whether the equipment used for the test was functioning properly, and other circumstances that may have affected the reliability of the chemical test.

DUI lawyer Bernie McEvoy has the skill and knowledge to challenge questionable BAC results and defend drivers against the prosecution. He has provided experienced representation to many people in Davidson and Williamson Counties, including in Nashville and Franklin. To arrange a free consultation, submit the contact form on our website or call our office at (615) 255-9595 during business hours or (615) 804-8779 on evenings and weekends. Attorney McEvoy also handles a wide range of other criminal cases, including sex offenses, domestic violence, and drug crimes.