-
Tempe
-
Lake Havasu City
-
Apache Junction
-
Parker
DUI Charge in Arizona?
There's Always a Defense.
An arrest is not a conviction, and a failed breath test is not the end of your case. Our founder, Matthew Lopez, reviews every stop, every test, and every report the state relies on, looking for the errors that get evidence suppressed and charges reduced. The strategy you choose now shapes everything that follows.
An arrest is an accusation, not a verdict. Arizona DUI cases are built from a chain of steps, the traffic stop, the roadside investigation, the arrest, the chemical test, and the lab analysis, and a weakness at any link can break the whole case. Prosecutors count on defendants assuming the breath machine is never wrong and the officer always followed the rules. Neither assumption holds up under scrutiny.
This page walks through the defenses that actually move Arizona DUI cases: what they challenge, why they work, and when they apply. Not every defense fits every case, but nearly every case has at least one genuine vulnerability worth pressing.
Matthew Lopez Law defends DUI charges across Arizona. Contact our firm for a confidential consultation.
Every DUI case begins with a stop, and every stop requires reasonable suspicion that a law was broken. Under the Fourth Amendment and Arizona law, an officer cannot pull you over on a hunch. If the stated reason for the stop does not hold up, such as a lane touch that never happened, a mistaken belief about a traffic law, or an anonymous tip with no corroboration, then everything obtained afterward can be suppressed. A successful challenge to the stop usually ends the entire case.
Arizona’s appellate courts have repeatedly addressed what does and does not justify a stop. The Arizona Judicial Branch publishes opinions that define these boundaries, and a defense attorney reviews the stop against that case law.
The three standardized field sobriety tests, horizontal gaze nystagmus, walk-and-turn, and one-leg stand, are far less reliable than juries assume. The National Highway Traffic Safety Administration sets precise administration standards, and even validated tests correlate imperfectly with actual impairment.
These tests are affected by conditions that have nothing to do with alcohol: inner-ear problems, neurological conditions, leg and back injuries, obesity, age over 65, uneven or sloped pavement, poor lighting, traffic noise, and improper footwear. When an officer deviates from the standardized protocol, or when a medical condition explains the performance, the test results lose their weight.
Arizona law criminalizes a BAC of 0.08 or more within two hours of driving. This creates a specific defense. Alcohol takes time to absorb, so a person’s BAC can still be climbing after they stop driving. Someone who was at 0.06 behind the wheel might test at 0.09 forty-five minutes later at the station. The number that matters is the level while driving, not the level at the station, and a forensic toxicologist can reconstruct the absorption curve to show the difference.
Breath testing is the most common form of DUI evidence and one of the most challengeable. Arizona uses the Intoxilyzer series, and these machines are only as reliable as their maintenance and operation:
Blood testing is often presented as the gold standard, but blood cases have their own vulnerabilities:
You can be charged with DUI in Arizona without driving. The “actual physical control” doctrine reaches a person sitting in a parked car. But it has limits. Arizona courts weigh factors like whether the engine was running, where the keys were, whether the person was asleep, the position of the seat, and whether the vehicle posed any immediate danger. Someone sleeping it off responsibly in a parked car, keys out of the ignition, has a real argument that they were never in actual physical control.
Miranda. Statements taken during custodial interrogation without Miranda warnings can be suppressed.
Right to counsel. Arizona gives DUI arrestees a limited right to consult an attorney before deciding on testing, as long as it does not delay the investigation. Denial of that right can affect the case.
Independent testing. Arizona law gives you the right to obtain your own independent chemical test. If police prevent this, the state’s evidence may be challenged.
Under ARS 28-1321, driving in Arizona means you have consented to chemical testing when lawfully arrested. Refusing triggers an automatic one-year license suspension, separate from the criminal case. But the officer must properly advise you of the consequences, and defects in that advisory, or in the refusal process, can be challenged at the MVD hearing and in court.
When the evidence has genuine weaknesses, the practical goal is often reduction to reckless driving under ARS 28-693. Unlike a DUI, reckless driving carries no mandatory jail and no ignition interlock requirement. A reduction preserves a clean DUI record and avoids the escalating penalties that come with a first DUI prior.
Every DUI case has a chain of evidence, and every link is a potential defense. The stop, the roadside tests, the chemical analysis, and the officer’s compliance with Arizona procedure all deserve scrutiny. Early review preserves evidence and keeps every option open.
We serve clients in Tempe, Mesa, Apache Junction, Lake Havasu, Parker, and statewide. Payment plans available. Every interaction confidential.
Contact us for a free consultation.
Every minute counts when you’re facing criminal charges in Arizona. Whether you were just arrested or have court next week, our team is ready to start building your defense right now. We offer free consultations and can start protecting your rights today with flexible payment plans that work for your budget.
Real person answers,
not voicemail
No obligation, no pressure
Start your defense with
minimal money down
Google Reviews
Successfully Defended
For Arizona Residents
Fighting For You
"*" indicates required fields
This will close in 0 seconds