Can a Wyoming DUI Be Dismissed?
It is one of the first questions people ask after a DUI arrest: is there any chance this goes away?
The answer is yes — but the path to a dismissal depends entirely on the facts of your case. There are two fundamentally different ways a Wyoming DUI charge can be dismissed, and they are not the same thing. Understanding the distinction matters before you make any decisions about how to proceed.
The First Path: Outright Dismissal
An outright dismissal means the charge is dropped entirely — not because you completed a program or served a probationary period, but because the evidence against you is legally insufficient or was obtained in violation of your constitutional rights. There is no guilty plea, no probation, no record of the charge being resolved against you. The case simply ends.
Outright dismissals in DUI cases typically result from one of several avenues:
The Traffic Stop Was Unlawful
Every DUI case begins with a traffic stop. Under the Fourth Amendment, law enforcement must have reasonable suspicion of a traffic violation or criminal activity before initiating a stop. That suspicion must be based on specific, articulable facts — not a hunch.
If a deputy pulled you over without the required legal basis, the stop itself is unlawful. When that happens, the evidence gathered as a result of the stop — the odor of alcohol, the field sobriety tests, the breath test result — can be suppressed, meaning the court excludes it from the case. Without that evidence, the prosecution typically cannot proceed, and the case is dismissed.
This is the Fourth Amendment operating exactly as it was designed to operate: excluding the fruits of unconstitutional police conduct. Ethan has won multiple DUI dismissals in Teton County after successfully arguing that deputies lacked reasonable suspicion for the initial traffic stop.
The Breath Test Was Administered Incorrectly
Wyoming law requires law enforcement to follow a specific operational checklist when administering breath tests. That checklist exists for a reason: breath testing is a scientific process, and deviations from required procedures compromise the reliability of the result.
Common grounds for challenging a breath test result include:
Failure to complete the operational checklist. Deputies are required to follow each step of the approved procedure. Skipping or incorrectly performing steps — including the required observation period before the test is administered — is a basis to challenge the result.
Improper calibration or maintenance. Breath test instruments must be maintained and calibrated according to established standards. Records of calibration and maintenance are discoverable, and deficiencies in those records can undermine the result.
Residual mouth alcohol. The required observation period before breath testing is designed to ensure that residual mouth alcohol — from a recent drink, a belch, or certain medical conditions — does not artificially inflate the result. Failure to observe that period calls the result into question.
When a breath test result is successfully challenged, the prosecution may lose its primary evidence of impairment, making a dismissal or favorable resolution far more likely. Ethan has obtained dismissals of multiple Teton County DUI cases after establishing that deputies failed to follow the required breath test procedures.
Field Sobriety Tests Were Improperly Administered
Standardized Field Sobriety Tests — the walk-and-turn, one-leg stand, and horizontal gaze nystagmus — are only valid indicators of impairment if administered correctly, under appropriate conditions, and evaluated against proper standards. Physical conditions, road surface, lighting, footwear, age, weight, and pre-existing medical or neurological conditions can all affect performance independent of alcohol consumption. An officer who deviates from the standardized administration instructions produces results that carry little scientific weight.
Blood Test Issues
When blood is drawn rather than breath tested, a different set of challenges applies. Blood test evidence depends on proper collection technique, correct labeling, unbroken chain of custody, appropriate storage conditions, and qualified laboratory analysis. Failures at any point in that chain can compromise the reliability of the result and provide grounds for a challenge.
The Prosecution Declines to Proceed
Sometimes the dismissal comes not from a court ruling but from a prosecutorial decision. When a defense attorney identifies and communicates significant evidentiary problems early — through a well-researched letter or pretrial meeting with the prosecutor — the prosecution may conclude that the case is not worth pursuing. This is another reason why having counsel involved as early as possible in a DUI case pays dividends.
How Outright Dismissals Are Pursued: Motions to Suppress and Motions to Dismiss
The legal problems described above — an unlawful stop, a defective breath test, an improper search — do not resolve themselves. They must be raised through formal pretrial motions filed with the court. Two types of motions are central to DUI defense: the motion to suppress and the motion to dismiss. They are related but distinct, and understanding the difference matters.
Motion to Suppress Evidence
A motion to suppress asks the court to exclude specific evidence from the case on the grounds that it was obtained in violation of the defendant's constitutional rights — most commonly the Fourth Amendment's protection against unreasonable searches and seizures.
In a DUI case, a motion to suppress might target the results of a breath or blood test, observations made during a traffic stop that lacked reasonable suspicion, or statements made by the defendant during a custodial interrogation that was not preceded by proper Miranda warnings. The motion sets out the legal basis for exclusion and asks the court to hold an evidentiary hearing at which the arresting officer testifies and is subject to cross-examination.
If the court grants the motion and suppresses the challenged evidence, that evidence cannot be used against the defendant at trial. The practical consequence is often significant: a DUI case without a breath test result, without the officer's observations of impairment, or without the defendant's own statements frequently cannot be proven beyond a reasonable doubt. The prosecution will often move to dismiss the charge rather than proceed to trial with the remaining evidence.
A suppression motion is not a guaranteed outcome — the court must be persuaded that a constitutional violation occurred. But it is one of the most powerful tools in a DUI defense because it attacks the foundation of the government's case rather than simply disputing the facts at trial.
Motion to Dismiss
A motion to dismiss asks the court to terminate the case entirely, without a trial. In DUI cases, motions to dismiss are most commonly filed when:
The charge is legally deficient. If the information or citation charging the defendant does not allege facts sufficient to constitute the offense — or alleges the wrong offense — dismissal may be appropriate as a matter of law.
The evidence is constitutionally tainted and nothing remains. When a motion to suppress is granted and the suppression of evidence leaves the prosecution with insufficient basis to proceed, a motion to dismiss is the natural next step. Rather than waiting for the prosecution to act, defense counsel can affirmatively move to dismiss the charge on the grounds that the remaining evidence cannot support a conviction.
A speedy trial violation has occurred. Wyoming law and the United States Constitution guarantee criminal defendants the right to a speedy trial. Wyoming Rule of Criminal Procedure 48 requires that a misdemeanor case be brought to trial within 180 days of arraignment absent good cause. Significant, unjustified delays attributable to the prosecution can provide grounds for dismissal.
The stop or arrest lacked probable cause as a matter of law. In some cases, the facts as recited in the police report — taken at face value — are legally insufficient to justify the stop or the arrest. Where no reasonable reading of the record supports the required legal standard, dismissal can be argued without the need for an evidentiary hearing.
The Second Path: Deferred Prosecution Dismissal (The "301 Deferral")
The second type of DUI dismissal in Wyoming is fundamentally different from an outright dismissal. It does not result from a flaw in the government's evidence. Instead, it is a negotiated resolution available to certain first-time offenders under Wyoming Statute § 7-13-301 — commonly called the "301 deferral" or simply "the deferral."
How It Works
Under the deferral, the defendant enters a guilty or no contest plea to the DUI charge — acknowledging the factual basis for the charge. The court then defers further proceedings, meaning it does not enter a judgment of guilt or conviction, and instead places the defendant on probation for a period of up to 36 months. The terms of probation typically include completing a substance abuse evaluation and any recommended treatment, performing community service, paying fines and court costs, and reporting to the court as required.
If the defendant successfully completes the probationary period, the court discharges the defendant and dismisses the case. Under Wyoming Statute § 7-13-301(d), that discharge and dismissal "shall not be an adjudication of guilt and is not a conviction for any purpose."
In plain terms: if you complete the deferral, there is no conviction on your record.
Who Qualifies?
The deferral is not available to everyone. The statutory requirements are specific:
No prior felony convictions. A defendant who has previously been convicted of any felony does not qualify.
First DUI only. The deferral is not available for a second or subsequent DUI violation. It applies only to first-offense DUI charges.
Only one deferral in a lifetime. Wyoming Statute § 7-13-301(e) is explicit: there shall be only one discharge and dismissal under this section, or under any similar provision of any other jurisdiction. If you have previously received a deferral — for a DUI or any other criminal charge, in Wyoming or elsewhere — you do not qualify. The deferral is a one-time opportunity.
Prosecutor consent is required. The deferral requires the agreement of both the defendant and the prosecution. The court cannot impose a deferral over the prosecutor's objection. Whether the prosecution agrees to a deferral can depend on the specific facts of the case, the county where the charge is filed, and the quality of the advocacy on your behalf.
BAC matters. The higher your BAC, the less likely a deferral is on the talbe.
CDL holders face additional restrictions. Commercial driver's license holders are subject to federal regulations that interact with Wyoming's DUI statutes in ways that can limit or eliminate deferral eligibility. If you hold a CDL, this is a critical issue to discuss with your attorney.
Prior criminal history may affect eligibility beyond the felony bar. The statutory requirements above define the hard legal limits on who can qualify for a deferral. But the deferral also requires the prosecutor's consent and is subject to the court's discretion — and both the prosecution and the court may consider your broader criminal history when deciding whether to agree to or approve a deferral. A defendant with a significant misdemeanor record, a history of prior arrests, or a pattern of conduct that suggests the current offense is not an isolated incident may find that the prosecution declines to offer a deferral even where no strict statutory bar applies. Whether your history supports or undermines a deferral request is one of the central questions your attorney will evaluate at the outset of your case.
What the Deferral Does — and Does Not — Do
It is important to be clear-eyed about what a deferred prosecution dismissal means in practice.
It is not a dismissal of the charges before any admission. Unlike an outright dismissal, the deferral requires a guilty or no contest plea at the outset. You are admitting the factual basis for the charge as a condition of entering the program.
WYDOT's administrative license suspension still applies. The Wyoming Department of Transportation's administrative action against your driver's license — including any suspension — proceeds independently of the criminal case and is not affected by the deferral. If you did not request a contested case hearing within 20 days of your arrest, that suspension has likely already taken effect regardless of how the criminal case resolves.
The record of arrest remains. A deferred prosecution dismissal is not the same as an expungement. The arrest will appear on your record, and in many contexts — background checks, professional licensing applications — the existence of a DUI arrest may still be visible even after a dismissal. What the deferral prevents is a conviction on your record.
Probation is a real obligation. The probationary period involves genuine requirements. Failing to comply — missing a report date, failing a drug or alcohol test, failing to complete required treatment — can result in the deferral being revoked and the original conviction being entered.
A completed deferral cannot be expunged under current Wyoming law. This is a critical limitation that is frequently misunderstood. Many clients assume that once the deferral is completed and the case is dismissed, they can later petition to have the arrest record expunged — effectively erasing the matter entirely from their history. However, the Wyoming Supreme Court's decision in Lynch v. State, held that records of a deferral disposition may not be expunged, even after the case is dismissed. Unless the legislature acts, this will continue to be the law in Wyoming.
Which Path Applies to Your Case?
These two types of dismissal are not mutually exclusive, and they are not the only two outcomes available. In some cases, the strongest path is to pursue an outright dismissal through pretrial motions — and if that fails, to fall back to a deferral negotiation. In others, the evidence against the defendant is strong, and the deferral represents the best available outcome for a first-time offender who wants to avoid a permanent conviction. In still others, the facts warrant neither — and a reduction to a lesser charge, such as reckless driving, may be the most realistic goal.
The right strategy depends on the specific facts of your case: how the stop was initiated, how the breath or blood test was administered, what the BAC was, whether you have prior convictions or a prior deferral, and what the prosecution's posture is likely to be. These are questions that require a careful review of the evidence — and they are exactly why having an experienced local attorney involved from the beginning makes a practical difference.
If you have been charged with a DUI in Teton County or the surrounding area, contact Teton Defense for a free consultation. Ethan Morris has won outright dismissals of multiple DUI cases in Teton County — including cases dismissed after breath test challenges and unlawful stop arguments — and has guided first-time offenders through the deferral process.
