If you’ve been cited or arrested for DUI, you might notice “DUI” being listed as 2 or 3 separate charges. This is often very confusing, especially when it is someone’s first offense. But this has to do with the fact that Tennessee’s DUI law, TCA § 55-10-401, like many other states’, has several, specific ways someone might commit DUI. If your case is still in a general sessions court, or in the pre-trial stage of criminal court, it’s very likely that the district attorney’s office will charge you with each specific DUI clause to “cover their bases” in a way.
DUI “Per Se”
DUI “Per Se” is the traditional DUI law that everyone is familiar with: It is illegal to drive if your blood alcohol content is 0.08% or greater by volume. “Per Se” is a Latin phrase meaning “intrinsically” or “by definition.” This law is called “Per Se” because it just defines anyone with that 0.08% BAC as “under the influence,” without taking into account whether their coordination, motor skills, or perception are actually influenced or impaired by the alcohol in their system. Of course, this number is not totally arbitrary; it is backed up by medical and scientific research and ought to apply to a significant number of people. But whether or not the alcohol is having a tangible effect on the specific individual being charged is not something this law is designed to contemplate. If the individual is above 0.08%, they are by definition too intoxicated to drive, regardless of how the alcohol is actually affecting them.
DUI “By Impairment”
We all generally understand that alcohol affects different people in different ways depending on a huge variety of medical and biological factors. The law has found 0.08% to be a reliable enough number to indicate a general point at which impairment can start to affect someone’s driving ability. But what if it goes the other way? What if you have a case where an individual is unusually impaired by lesser amounts of alcohol? Situations like this are why many states have what is referred to as an “impairment” law. Georgia uses the phrase “less safe” in their actual law, and the majority of states have a law with the same sentiment. “Impairment” DUI laws make it illegal to drive if the alcohol or drugs in your system “impair” you to the point where it is “less safe” for you to drive than it would be if you were sober.
“Impairment” laws are a bit of a double edged sword, however. By having these laws, it gives the state the ability to prosecute individuals for DUI who are clearly impaired but possibly below the 0.08% threshold. On the other hand, proving subjective opinions, like whether someone is “too impaired” or “less safe” to drive than they normally are, beyond a reasonable doubt is obviously tougher than proving the 0.08% number.
Other DUI Definitions
There are also many other types of DUI clauses that the state charges an individual with prior to deciding on just the one or two they will actually pursue. Some states will have a separate clause for a “drug” DUI that is different from their “alcohol” DUI. Some states might have DUI laws specific to the controlled substance they believe was used. Some states have a lower “Per Se” threshold for individuals they see as posing a higher risk when impaired: in Tennessee, for those operating CMV vehicles the “Per Se” threshold is 0.04%, and for those under 21 years old the threshold is 0.02%.
Regardless, if the state’s attorney on your case suspects that one or more DUI laws they have available might apply, it is likely that you will initially be charged with all of them, prior to the state deciding on which ones they might be most likely to prove in court.