Probable cause and breath tests in Tennessee DUI cases

There are many ways to identify drunk drivers in Tennessee and across the country, according to NHTSA. However, prosecutors tend to rely on toxicology test results showing a blood alcohol level of .08 percent or higher in DUI cases. These tests may be performed using breath testing equipment or blood tests, but police officers must have probable cause to pull a vehicle over and order such a test.

Police sometimes suspect that motorists are drunk when they see vehicles being driven erratically. Physical signs of impairment that could lead to a breath test or blood test request include watery or bloodshot eyes, slurred speech and the odor of alcohol. In many cases, drivers give police the probable cause they need by admitting that they consumed alcohol before getting behind the wheel.

Breath testing equipment has become more sophisticated and reliable in recent years, but the results these devices provide may not be reliable in all situations. The results of breath tests are sometimes challenged when police officers have failed to follow strict protocols while administering them. In addition, medical conditions including diabetes and gastric reflux disorder can influence the outcome of these tests. Tennessee is an implied consent state; therefore, motorists who refuse to submit to a breath test risk losing their driving privileges for a year or longer.

While experienced criminal defense attorneys may encourage their clients to follow the lawful orders of police officers, they could also remind them of their constitutional rights and ask them to make no statements or admissions. Attorneys may be able to ask prosecutors to dismiss drunk driving charges when their clients have remained silent and the existence of probable cause is questionable.

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