Driving Dangerously Drunk on Arizona’s Freeways: What State v. Merrill Means for You
NOTICE: This case is a memorandum decision which means it is not for official publication under Arizona Supreme Court Rule 111(c). The decision is not precedential and may be cited only as authorized by rule. Although not official precedent it does give an indication of what the court of appeals thinks about these issues.
A 2024 Arizona Court of Appeals ruling says you can be convicted of felony endangerment alongside a DUI — even if there was no crash. Here’s what every Arizona driver needs to know.
After a DUI arrest in Arizona, you have only 30 days to request an MVD hearing or your driver’s license is automatically suspended. Learn about Arizona DUI penalties →
📋 Case at a Glance: State v. Merrill
What Happened in This Case?
One night in October 2021, two women — identified only as D.D. and R.D. to protect their privacy — were driving on Interstate 17 in Yavapai County. When they pulled off the freeway to switch drivers, they spotted Tiffany Lee Merrill driving the wrong way on the off-ramp. They honked and flashed their lights. Instead of pulling over, Merrill turned her car around and followed them back onto the freeway.
For the next 10 to 15 minutes, Merrill drove aggressively alongside D.D. and R.D. — closely behind them, in front of them, and parallel to them. She repeatedly veered into their lane. D.D. slowed to around 25 miles per hour and turned on her hazard lights. At one point, Merrill stopped her car diagonally in front of them on the freeway, forcing all other traffic to swerve around both vehicles. When D.D. drove around her, Merrill got out and hit their car with her hand, then got right back in and resumed tailgating them. R.D. called 911 and described Merrill’s car and license plate.
A state trooper spotted Merrill’s car, observed it swerving, and conducted a traffic stop. The trooper noticed Merrill’s eyes were bloodshot and watery, her breath smelled of alcohol, and she admitted to having a drink earlier that night. She consented to a field sobriety test, which indicated impairment. A blood draw — taken outside the two-hour post-driving window — came back at .065. A forensic scientist then used retrograde BAC analysis to estimate that Merrill’s BAC at the time of driving would have been between .073 and .09.
Key Legal PointA BAC below the legal .08 limit at the time of the blood draw does not automatically mean you were under the limit while driving. Forensic retrograde analysis can be used to calculate a higher estimated BAC at the time of the incident. A skilled DUI attorney can challenge the assumptions in that analysis.
What Was Merrill Charged With?
A grand jury indicted Merrill on four counts in November 2021:
- Counts 1–2: Aggravated DUI (driving while impaired / driving with a BAC of .08 or higher, while going the wrong way), under A.R.S. §§ 28-1381, 28-1383
- Counts 3–4: Felony endangerment (naming D.D. and R.D. separately as victims), under A.R.S. § 13-1201
During trial, Count 1 was dismissed by the trial court. The jury then convicted Merrill of the lesser-included offense on Count 2 (standard DUI, rather than aggravated DUI) and of both felony endangerment counts, finding both to be dangerous offenses.
The sentences: 74 days on the DUI count, and concurrent mitigated prison terms of 1.5 years each on the endangerment counts.
What Did the Arizona Court of Appeals Decide?
1. No collision required for felony endangerment
Merrill argued the endangerment convictions should be thrown out because nobody was actually hurt and no collision occurred. The Court of Appeals rejected this argument clearly: Arizona’s felony endangerment statute (A.R.S. § 13-1201) “criminalizes conduct posing a substantial risk rather than creating an observable result.” The court pointed to Merrill’s repeated lane changes, blinding headlight use, forcing D.D. to the edge of the road, and stopping diagonally across a freeway as more than enough evidence of a substantial risk of imminent death.
2. Jury instructions were not erroneous
Merrill also argued the endangerment instruction given to the jury was legally flawed, comparing it to an instruction that had been overturned in an earlier case, State v. Doss (1998). The court disagreed. The instruction here correctly described both the required mental state (recklessness) and the required act (actually placing someone at substantial risk of imminent death). The court also noted that because Merrill’s own attorney had requested a nearly identical instruction, any error was invited and therefore waived.
⚖️ What This Means for You
- Dangerous driving behavior can add felony charges to a DUI. If prosecutors believe your driving placed others at a substantial risk of death — swerving, tailgating aggressively, blocking traffic — you can face felony endangerment on top of DUI, even on a first offense.
- No accident needed. Courts have made clear that endangerment doesn’t require a collision, a near-miss, or physical injury. The risk itself is enough.
- Your BAC at the blood draw isn’t the end of the story. If your blood is drawn more than two hours after the alleged impaired driving, the prosecution may use retrograde analysis to argue your BAC was higher while you were actually driving. This analysis involves assumptions that can be challenged.
- Lesser-included offenses matter. As this case shows, a jury can convict on a lesser charge even when a higher-level count fails. Understanding the full range of possible outcomes is critical before deciding how to handle your case.
- A single incident can produce multiple convictions. Merrill was sentenced on three separate counts from one night. Each victim can be a separate count, and DUI and endangerment can stack.
- You need to act fast. The 30-day MVD deadline is real and unforgiving. Losing your license automatically while your criminal case is still pending can devastate your work and family life.
The Arizona Laws at the Center of This Case
A.R.S. § 28-1381 – Standard DUI: Driving with a BAC of .08% or higher, or while impaired to the slightest degree by alcohol or drugs. This is what Merrill was ultimately convicted of (as a lesser-included offense).
A.R.S. § 28-1383 – Aggravated (Felony) DUI: Applies to DUI while driving the wrong way on a highway, among other circumstances. This is what Merrill was originally charged with — and what the trial court dismissed on Count 1.
A.R.S. § 13-1201 – Felony Endangerment: A person commits felony endangerment by recklessly endangering another person with a substantial risk of imminent death. This is a Class 6 felony in Arizona.
To learn more about the full range of Arizona DUI penalties, visit the DUI Penalties page.
Gordon Thompson is an Arizona DUI and criminal defense attorney licensed since 1982, with 47 years of experience and more than 6,000 cases handled. His practice is limited exclusively to DUI and criminal defense — he handles no other area of law. He earned his law degree from Syracuse University College of Law and is a member of the State Bar of Arizona. Every client works directly with Gordon — not a paralegal or junior associate.Read full bio →
🔗 Related Resources on This Site
- Arizona DUI Defense Strategies — How Gordon challenges DUI evidence
- Arizona DUI Penalties — Full breakdown of consequences by charge type
- Complete Guide to Arizona Misdemeanor DUIs — Step-by-step walkthrough of the DUI process
- Recent Good Case Results — Real outcomes from Gordon’s practice
- DUI Case Studies — In-depth look at how specific cases were handled
- Flat Fee Agreement — All-inclusive pricing with no hidden costs
- Frequently Asked Questions — Common DUI questions answered
- Areas Served in Arizona — Courts where Gordon regularly appears
❓ Arizona DUI & Felony Endangerment — Frequently Asked Questions
These answers are based on Arizona law and are provided for general information. Every case is different. For advice specific to your situation, contact Gordon Thompson directly.
Yes. Arizona law (A.R.S. § 13-1201) allows prosecutors to charge felony endangerment whenever a person recklessly creates a substantial risk of imminent death for someone else — even while also charging DUI. State v. Merrill (2024) confirms that dangerous driving behavior such as swerving into another lane, blinding other drivers, or blocking freeway traffic is enough to support both charges at once. Each person who was endangered can be a separate count.
See more about DUI defense strategies in Arizona.
No. Arizona courts have consistently held that endangerment criminalizes conduct that poses a substantial risk — not conduct that produces an observable result like a collision or injury. In State v. Merrill, the Court of Appeals upheld two felony endangerment convictions even though no collision or injury occurred. The dangerous driving behavior itself was enough.
Retrograde BAC analysis is a scientific method forensic experts use to estimate what your blood alcohol level was at an earlier point in time, based on a later test result. In Arizona, if your blood is drawn more than two hours after the alleged impaired driving (as happened in State v. Merrill), prosecutors may use retrograde analysis to estimate your BAC at the time you were driving.
This analysis relies on average alcohol metabolism rates and assumptions about factors like food intake, drinking timeline, and body weight. A skilled DUI defense attorney can challenge these assumptions. Learn about Gordon’s approach to DUI defense.
Under A.R.S. § 28-1381, it is illegal to drive with a BAC of .08% or higher, or while impaired to the slightest degree by alcohol or drugs. Arizona also has:
- Extreme DUI (A.R.S. § 28-1382) — BAC of .15 or higher
- Super Extreme DUI (A.R.S. § 28-1382) — BAC of .20 or higher
Both Extreme and Super Extreme DUI carry mandatory minimum jail sentences that cannot be suspended on a first offense. See the full breakdown on the Arizona DUI penalties page.
Felony endangerment under A.R.S. § 13-1201 is a Class 6 felony in Arizona. In State v. Merrill, the defendant received concurrent mitigated prison terms of 1.5 years each on two endangerment counts. Penalties can be more severe if the jury finds the offense involved a deadly weapon or dangerous instrument — which the jury did in Merrill’s case. If you are facing endangerment charges alongside a DUI, the potential consequences are significantly more serious than a standard DUI alone.
A DUI arrest in Arizona automatically triggers an MVD license suspension process. You have only 30 days from the date of arrest to request a Motor Vehicle Division hearing to contest the suspension. Miss that deadline and your license is suspended automatically — no exceptions.
Gordon Thompson files this MVD hearing request immediately as the first step in every DUI case. See the full consequences of a DUI in Arizona.
Yes. Possible outcomes include dismissal, a reduced charge, or a not-guilty verdict at trial. State v. Merrill itself is a good example: one of the original aggravated DUI counts was dismissed by the trial court, and the jury convicted on a lesser-included offense rather than the full aggravated charge.
Grounds for challenging a DUI include an unlawful traffic stop, improper blood or breath test procedures, faulty retrograde BAC analysis, or constitutional violations. Gordon Thompson has achieved dismissals and reduced charges across 47 years and 6,000+ cases. See recent good results.
Standard DUI under A.R.S. § 28-1381 is typically a misdemeanor. Aggravated (felony) DUI under A.R.S. § 28-1383 applies when you:
- Drive on a suspended or revoked license
- Have a passenger under 15 years old in the vehicle
- Have a prior felony DUI conviction, or
- Drive the wrong way on a highway (as in State v. Merrill)
Aggravated DUI is a Class 4 or Class 6 felony in Arizona and carries mandatory prison time. Gordon Thompson defends clients against all levels of DUI charges. Learn about DUI defense.
Gordon Thompson charges an all-inclusive flat fee of $2,800–$3,300 for most misdemeanor DUI cases in Arizona. There is no separate trial fee, no hidden costs, and affordable payment plans are available. This fee covers everything from the initial MVD hearing request through trial if necessary. See the full flat fee agreement.
Take these steps as quickly as possible:
- Do not make statements to law enforcement beyond providing basic identification.
- Contact a DUI attorney immediately — ideally within 24 hours of your arrest.
- Protect your license: An attorney must request your MVD hearing within 30 days or your license is automatically suspended.
- Document everything you remember about the stop — location, time, what the officer said and did, any field sobriety tests performed.
- Don’t post on social media about the incident.
Gordon Thompson handles the MVD hearing request as the very first step for every new client. Contact Gordon now or call (602) 467-3680.
Facing DUI or Endangerment Charges in Arizona?
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Legal Disclaimer: This article is provided for general informational and educational purposes only and does not constitute legal advice. Reading this article does not create an attorney-client relationship. The outcome of State v. Merrill is presented for informational purposes; every criminal case involves unique facts and circumstances. If you are facing DUI or criminal charges in Arizona, consult with a licensed Arizona attorney about your specific situation. Gordon Thompson is licensed to practice law in Arizona and New York. Past results do not guarantee future outcomes.
Page authored by Gordon Thompson, Arizona State Bar licensed attorney, licensed since 1982. Last reviewed June 2026.