Driving while drunk is a criminal offense in every single state and Washington D.C. Most of these jurisdictions use either the term Driving While Intoxicated (DWI) or Driving Under the Influence (DUI) when codifying these offenses. Although every state differs slightly when defining what drunk driving is and how it will be punished, there are quite a few overlapping qualities.

This is especially true when it comes to what kinds of evidence the police can gather and what prosecutors can use in a trial. Here is a short guide to how most states define and charge drunk driving offenses, and what kinds of evidence they might gather against you.

What Is the Legal Level of Intoxication?

Although most people think of just the general .08 blood alcohol content (BAC) percentage, there are actually three different levels of classification for DUI/DWI purposes. The .08% is the per se level and the most commonly used. “Per se” intoxication is the BAC percentage that qualifies as a DUI for every adult of legal drinking age in every single state. As stated before, this is the most commonly known and used DUI law on the books in most jurisdictions. But there are two other levels as well.

There are also “zero tolerance” BAC levels, which is the maximum legal amount that a person under the drinking age may have in their system before earning a DUI. In most states, this level really is zero tolerance, with the percentage being 0.00%. There are a few states where BAC can measure 0.01% or 0.02% legally, so check the laws in your state.

Finally, there is the enhanced penalty BAC level, where if your BAC tests about a certain percentage, the possible punishments for DUI conviction are more serious. These levels start at 0.15% as the minimum starting point and go up to 0.20%, depending on the state.

What Types of Evidence Are Considered in a Dui Case?

If you are arrested for DUI, you are entitled to a trial where a judge or jury will be presented evidence of your intoxication. While specifics may vary by state, there are a few basic categories that are common across jurisdictions. Most of these have been Constitutionally tested and approved by judicial review:

  • Physical evidence: If someone is pulled over and an open or empty container of alcohol is found in the driver’s possession, this can be used as evidence of intoxication; 
  • Officer observations: The arresting officer’s testimony can be used in a trial to describe the defendant’s behavior to support a DUI claim. The may describe erratic driving like swerving, speeding, or running lights, and will look for bloodshot eyes, the smell of alcohol, and slurred speech when they talk to the driver;
  • Field sobriety tests: The National Highway Traffic Safety Administration (NHTSA) endorses a set of three sobriety tests, and most states have their own version of one of these three. Field sobriety tasks include checking balance and observing physical reactions like eye movement, and the officer uses these tests as well as the driver’s ability to obey direction as one way of determining impairment; and
  • Chemical tests: These are the breathalyzer, urine, and blood alcohol content (BAC) tests that most people know. They use bodily fluids to determine if the person is impaired, and the level of impairment.

What Evidentiary Issues Can Come up in My Dui Case?

Along with their own statutes defining drunk driving, every state also has their specific rules of evidence that must be obeyed in a criminal trial. Going through the process of an arrest is a good way to identify possible evidentiary issues in your case.

The first step to a DUI case is usually when the officers pulls the defendant over. They must be able to article probable cause for why the think the defendant is intoxicated, which is where observations like speeding and swerving come in, as well as seeing bottles or smelling alcohol on the driver’s breath. They will put this in a report, but in some states may be required to testify personally to avoid hearsay issues.

The next step in the stop is for the officer to administer a test to determine intoxication levels. They can use a field sobriety test, a chemical test, or both. This is where an officer’s dashcam or body camera footage may be used as well. The question of refusing either one often comes up when drivers are pulled over or arrested for DUI, and there is no easy answer there. 

States are increasingly making it more difficult and more costly for the accused person to refuse, and every state has different laws regarding refusal.  Be sure to check your state’s laws or consult with a criminal defense attorney

Do I Need an Attorney for My Dui Case?

Yes. Being arrested and convicted of DUI/DWI has serious legal consequences that can follow you for years. Not only is it incredibly expensive, but you can have your license suspended and even spend time in jail. If you are arrested or charged, you need to seek the services of a criminal defense attorney that specializes in DUI/DWI cases as soon as possible. They can talk you through all your legal options and make sure all of your rights are protected.