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Arizona is known for its strict DUI enforcement, but one question often confuses drivers: Can you be arrested for DUI if you pass a breath test? The answer is yes. While breath test results often play a major role in DUI cases, they are not the only factor used to determine impairment. In fact, Arizona law allows for DUI arrests based on behavioral signs, physical symptoms, and officer judgment—even when chemical tests do not confirm a high blood alcohol content (BAC).
This issue arises most often when a driver appears impaired but registers a BAC below the legal limit of 0.08%, or even 0.00%. In these cases, officers rely on other observations such as slurred speech, poor coordination, confusion, or the presence of drugs. Arizona’s legal standard for DUI includes the phrase “impaired to the slightest degree,” which broadens the criteria beyond alcohol-specific tests.
If you’re driving in Arizona, it’s important to understand that passing a breath test does not guarantee you won’t be arrested. A DUI charge can be based on a variety of factors, especially if the officer believes you’re impaired by prescription medication, drugs, or other substances not detected by a breathalyzer. This article breaks down how DUI arrests happen without failed breath tests, why it’s legal, and what drivers should be aware of during a stop.
Arizona’s “Slightest Degree” Standard for DUI
One of the key reasons you can be arrested without failing a breath test in Arizona is the state’s use of the “impaired to the slightest degree” standard. This legal phrase means that any observable impairment, regardless of BAC, can be enough to justify a DUI charge. If an officer believes your ability to drive has been affected in any way—from alcohol, drugs, or a combination—you can be arrested on the spot.
This standard is found in Arizona Revised Statutes §28-1381(A)(1). It allows for enforcement even when chemical test results do not exceed the legal threshold. This means you could blow 0.04% on a breath test, but still be considered impaired based on your behavior, coordination, or inability to follow instructions.
Arizona’s law does not require a driver to be “drunk” in the traditional sense. Instead, it focuses on whether you are safe to operate a vehicle. Subtle signs like drifting in a lane, delayed reactions, or confusion can trigger further investigation. If these behaviors are present, and the officer suspects a substance is affecting your ability to drive, you could be placed under arrest—even if your breath test is clean.
This law is designed to give law enforcement flexibility in situations where impairment is obvious but not fully confirmed by alcohol testing.
Other Substances That Don’t Show on Breath Tests
Another major reason you can be arrested without failing a breath test is that breathalyzers only detect alcohol. They do not detect drugs, including both illegal substances and prescription medications. In Arizona, driving under the influence of any impairing substance—even legally prescribed drugs—can result in a DUI charge if your ability to operate a vehicle is affected.
Examples of substances not detected by breath tests include:
- Marijuana (even medical use)
- Opiates and painkillers
- Anti-anxiety medications like benzodiazepines
- Sleep aids and muscle relaxants
- Illegal narcotics
Arizona law does not distinguish between legal and illegal drugs when it comes to DUI enforcement. If you’re found to be impaired, it doesn’t matter whether the substance was prescribed to you or not.
In situations where impairment is suspected but a breath test returns a 0.00% BAC, officers often request a blood or urine test to detect other substances. Refusing these tests can lead to license suspension under Arizona’s implied consent laws. These non-alcohol cases are treated just as seriously as alcohol-related DUIs and may result in the same penalties.
Officer Observations Carry Legal Weight
Even without a failed breath test, an officer’s observations alone can trigger a DUI arrest in Arizona. Police officers are trained to identify signs of impairment, and their judgment plays a significant role in DUI cases. During a traffic stop, they watch closely for physical cues that suggest a driver is not in full control of their faculties.
Common observations include:
- Bloodshot or watery eyes
- Slurred or slow speech
- The smell of alcohol or marijuana
- Inability to focus or respond appropriately
- Stumbling or swaying
- Confusion about location or time
These signs, when combined with erratic driving behavior or inconsistent answers during questioning, can form the basis of probable cause for an arrest. Arizona courts generally uphold officer judgment in these cases, especially when it is supported by written reports, dashcam footage, or bodycam recordings.
Field sobriety tests also play a role here. Even if a breath test is passed or not administered, poor performance on coordination tests can support an arrest decision. In Arizona, all of this evidence is viewed collectively, not in isolation, meaning the officer’s overall impression often carries significant weight in court.
Prescription Medications and DUI Arrests
Many drivers are surprised to learn that prescription medications can result in a DUI arrest, even when taken exactly as prescribed. In Arizona, it is illegal to drive while impaired by any drug, including medications for anxiety, pain, depression, or sleep. Breath tests cannot detect these substances, which is why DUI arrests sometimes occur without any alcohol present.
Common medications that can impair driving include:
- Hydrocodone (Vicodin)
- Alprazolam (Xanax)
- Diazepam (Valium)
- Ambien or other sleep medications
- Codeine-based cough syrup
These drugs can slow reaction time, reduce coordination, and cause drowsiness—all of which may affect driving performance. Officers who notice signs of impairment may arrest the driver and request a blood test to confirm the presence of prescription drugs.
Arizona law focuses on impairment, not legality. Even if the drug was legally prescribed, drivers are still responsible for ensuring they are safe to drive. There is no special exemption for medical necessity. If the officer believes the medication has affected your ability to operate a vehicle safely, you can be arrested and charged just like someone who is intoxicated.
Field Sobriety Tests and Physical Evaluation
In cases where the breath test is passed or not used, field sobriety tests become especially important. These standardized tests are designed to detect motor skill impairment, which may not be visible otherwise. Arizona police officers use tests such as the walk-and-turn, one-leg stand, and horizontal gaze nystagmus (HGN) to assess coordination and attention.
Failure on any of these tests can be used as evidence of impairment. Even minor mistakes—such as starting too soon, stepping off the line, or using arms for balance—can be viewed as signs that the driver is not in full control of their body. Officers document these failures in detail and often rely on them to justify an arrest.
In addition, officers may conduct non-standard evaluations based on their training. These include checking for eye dilation, pulse irregularities, or body tremors that can indicate drug use. Some officers are trained as Drug Recognition Experts (DREs) and may use a structured 12-step evaluation to determine impairment from non-alcohol substances.
These physical evaluations become a central part of the arrest decision when a breath test shows a BAC of 0.00%. They help fill in the gaps and allow the officer to justify taking the driver into custody.
FAQ
Can I be arrested for DUI in Arizona if I blow 0.00% on a breath test?
Yes. If the officer believes you’re impaired by drugs or other substances, you can be arrested.
Do breath tests detect marijuana or prescription drugs?
No. Breathalyzers only detect alcohol. Drugs require blood or urine tests.
What if I pass all sobriety tests but the officer still arrests me?
Officers can still arrest based on overall observations or erratic behavior.
Are prescription medications a valid DUI defense in Arizona?
Not automatically. If you’re impaired, even legal medications can lead to a DUI.
Can I refuse a blood or urine test in Arizona?
You can refuse, but it triggers an automatic 12-month license suspension under implied consent laws.
What if I wasn’t driving dangerously? Can I still be arrested?
Yes. Arizona allows DUI arrests based on impairment, not just driving behavior.
Is officer judgment enough to convict me of DUI?
In many cases, yes—especially when supported by test results or observed behavior.
Conclusion
In Arizona, DUI arrests are not limited to those who fail a breath test. You can be arrested—and convicted—based on officer observations, field sobriety tests, and signs of drug or prescription medication impairment. The law focuses on whether you were impaired, not just your BAC. This means you’re legally responsible for being in full control of your faculties, regardless of what substance may be involved.
Drivers often assume passing a breath test is enough to avoid trouble, but in Arizona, that’s not the case. If you’re pulled over and show signs of impairment, even a 0.00% BAC result may not prevent an arrest. Understanding how these laws work is essential for staying safe and avoiding unexpected legal consequences.
To explore how DUI arrests unfold during a traffic stop, check out What Triggers a DUI Arrest During a Traffic Stop. For a deeper dive into the foundation of DUI law in Arizona, read our full guide on How DUI Laws Work.