Most people know that it's illegal to drink and drive in Arizona, but what many people don't know is that Arizona is a zero tolerance state when it comes to drunk driving. Arizona DUI law actually makes it illegal to drive if you are "impaired to the slightest degree", regardless of your Blood Alcohol Concentration (BAC). That means you can be under the "legal limit" of 0.08% BAC and still be arrested for Driving Under the Influence (DUI).

Types of DUI Offenses in Arizona

Under Arizona law, it is illegal to drive under the influence of intoxicating liquor, any drug, a vapor-releasing substance containing a toxic substance, or any combination of liquor, drugs, or vapor-releasing substances if your BAC is 0.08% or greater or if you are “impaired to the slightest degree”, regardless of your BAC. Arizona recognizes three different levels of impairment for misdemeanor DUI offenses: Standard DUI, Extreme DUI, and Super Extreme DUI. The higher your BAC is within two hours of being in actual physical control of a vehicle, the higher level of charge you are eligible to receive. However, you can also be charged with a DUI offense if you are "impaired to the slightest degree" while under the influence.

You can be charged with Standard DUI if your BAC is at least 0.08% but less than 0.15%, or if you are impaired to the slightest degree. Extreme DUI charges can be filed against you if your BAC is at least 0.15% but less than 0.20%. If your BAC 0.20% or higher, you can be charged with Super Extreme DUI.

Arizona law also includes a felony-level DUI charge called Aggravated DUI. These aggravating factors include:

• A child under the age of 15 was in the vehicle
• The driver had 2 or more previous DUI offenses in the last 7 years
• The driver had a revoked or suspended driver’s license
• The driver had an ignition interlock device installed on the car
• The driver was going the wrong way on the highway

Impaired To the Slightest Degree Standard DUI

It's a common misconception that it is legal to drink and drive if your BAC is less than 0.08%. In Arizona, however, this is not true. Arizona law allows you to be charged with an "impaired to the slightest degree" Standard DUI even if you take a breath test and your blood alcohol content is below 0.08%. A DUI charge in Arizona is a first class misdemeanor, regardless of if you are charged with having a BAC of 0.08% or of being impaired to the slightest degree. A misdemeanor DUI conviction can result in jail time, substantial fines, and a driver's license suspension.

So what does "impaired to the slightest degree" mean? The general understanding is that impaired to the slightest degree essentially means "tipsy". This means that if police officers can find enough evidence by observing your behavior to prove beyond a reasonable doubt that you were impaired at all, you can be convicted of DUI regardless of your BAC.

How Law Enforcement Decides if You Are Impaired To the Slightest Degree

Unlike BAC levels, "impaired to the slightest degree" is a subjective standard. When law enforcement pulls a driver over, they will be looking for signs of possible impairment such as:

• If there is a smell of alcohol in the car or on the driver's person or breath
• If the driver's eyes are bloodshot or watery
• If the driver's speech is slurred
• If the driver's driving was poor or erratic before being pulled over
• If the driver's fine motor skills are slowed or clumsy
• If the driver's behavior and/or attitude show possible signs of impairment
• If the driver can focus, concentrate, and follow instructions

Law enforcement can also request that you participate in Field Sobriety Testing. Three Standard Field Sobriety Tests (SFSTs) are endorsed by the National Highway Traffic Safety Administration (NHTSA). The purpose of the tests is to allow police officers to collect more evidence that you are impaired to the slightest degree, as a DUI charge that is not based on BAC relies heavily on the police officer's observations.

The SFSTs are designed to test your sense of balance, coordination, physical reflexes, and memory for standard indicators of impairment by drugs or alcohol. Since there is no objective test like a breathalyzer to base an impaired to the slightest degree charge on, law enforcement will use field sobriety testing as a way to gather more evidence against you.

The three SFSTs are:

1. Horizontal gaze nystagmus (HGN)

The HGN test requires you to follow an object with your eyes. During this test, the police officer will observe you and look for particular eye movements that have been deemed a common sign of impairment.

2. Walk-and-turn (WAT)

The WAT test requires you to walk heel-to-toe for nine steps, turn around, and walk heel-to-toe back to where you started. During this test, the police officer will assess your apparent ability to follow instructions, keep your balance, and walk in a straight line.

3. One-leg stand (OLS)

The OLS test requires you to stand on one leg for 30 seconds. During this test, the police officer will be looking for evidence that your balance and coordination are impaired.

While the SFSTs were designed to test balance, reflexes, coordination, and memory for evidence of impairment, you could perform poorly on field sobriety tests for a variety of reasons besides intoxication. Unfortunately, the SFSTs have no method for differentiating between poor performance because of intoxication and poor performance for other reasons. For example, you could do poorly on the SFSTs due to poor balance, medical problems, being overweight, exhaustion, illness, or advanced age, and then be arrested for DUI because law enforcement concludes you are impaired.

If a police officer asks you to participate in field sobriety testing, Arizona law gives you the right to refuse without any legal consequences. Exercising this right can help you avoid a wrongful arrest for impaired in the slightest degree DUI.

What To Do if You Are Arrested for Impaired in the Slightest Degree DUI

If you've been arrested for impaired in the slightest degree DU, a skilled criminal defense attorney has many options for fighting a conviction, especially if you took a breath test and your BAC was under 0.08%. Because impaired in the slightest degree DUI is so subjective, there is ample room for an attorney to attack the evidence the state has against you, making it easier to defend than DUI cases based on BAC test results.

An attorney can argue that you were not impaired or that you performed poorly on field sobriety testing for a reason besides impairment by drugs or alcohol. Remember, to be convicted of an impaired in the slightest degree Standard DUI, it's not enough for the prosecutor to simply prove that your driving was impaired. The prosecutor has to be able to prove that you were impaired because you used drugs, alcohol, a vapor-releasing substance containing a toxic substance, or any combination of these. If your attorney can point to an alternate explanation for your impaired driving, your charges can be dropped or reduced.