Local DUI Laws

A DUI arrest in Nevada doesn’t happen at random. Law enforcement officers must observe certain behaviors or gather enough evidence during a traffic stop to justify an arrest for driving under the influence (DUI). Understanding what actually triggers a DUI arrest can help Nevada drivers recognize how the process unfolds, what signs police are trained to watch for, and what legal thresholds determine when an arrest can be made.

DUI laws in Nevada apply to more than just alcohol. An arrest can also occur if a driver is suspected of being under the influence of drugs, whether those substances are illegal, prescription, or even over-the-counter. However, alcohol remains the most common factor in DUI cases statewide.

The steps leading up to a DUI arrest generally start with a traffic stop. From that point, the officer’s observations—combined with any field sobriety or chemical tests—can result in a full arrest and further legal consequences. While no two situations are identical, there are consistent signs and procedures that law enforcement follows when evaluating potential impaired driving.

This article will break down the common behaviors, test results, and procedural factors that can trigger a DUI arrest in Nevada. If you’re driving in the state—whether you’re a resident or just visiting—it’s important to understand what law enforcement is looking for and how those signs contribute to a formal arrest decision.

Observable Driving Behavior That Leads to a Traffic Stop

The first stage in most DUI arrests is a routine traffic stop. In Nevada, police officers must have a valid reason—called reasonable suspicion—to pull someone over. This typically means they observed a traffic violation or erratic driving behavior that suggested impairment.

Common driving behaviors that may lead to a DUI-related stop in Nevada include:

• Weaving or drifting between lanes
• Driving significantly below the speed limit
• Failing to signal or obey traffic signs
• Sudden stops or delayed reactions
• Nearly hitting objects or other vehicles
• Inconsistent braking

These behaviors on their own don’t prove intoxication. However, they can give an officer legal grounds to initiate a stop. Once the driver is pulled over, the officer begins evaluating the situation more closely for signs of impairment.

Even a minor traffic infraction—like a broken tail light or rolling through a stop sign—can serve as a basis for a lawful stop. If the officer then suspects DUI based on observations, the stop may escalate into a full investigation.

In short, most DUI arrests start with some form of visible driving issue, whether directly related to impairment or not. That’s why it’s essential for all drivers to operate vehicles responsibly and remain alert on Nevada roads.

Initial Observations by Law Enforcement

After initiating the stop, a police officer will begin collecting information through conversation and visual assessment. Nevada law allows officers to consider a wide range of behavioral cues when deciding whether to investigate further for DUI.

Key signs that may trigger suspicion include:

• Slurred or slow speech
• Bloodshot or watery eyes
• Strong odor of alcohol or marijuana
• Difficulty producing license and registration
• Confused or delayed responses to questions

Officers are trained to note not only what the driver says, but also how they say it. Fumbling with documents, repetitive speech, or an inability to follow simple instructions can all raise red flags.

It’s important to note that these signs do not confirm impairment by themselves. However, they contribute to an officer’s overall judgment and can justify the next step in the process: field sobriety testing.

Initial observations are especially important in Nevada DUI stops involving substances other than alcohol. When drugs are suspected, visible signs such as pupil dilation, agitation, or drowsiness may be the primary indicators.

Field Sobriety Tests and Impairment Clues

If the officer suspects impairment, they may ask the driver to step out of the vehicle and perform field sobriety tests (FSTs). These are standardized physical tasks used to assess coordination, balance, and cognitive function.

In Nevada, common field sobriety tests include:

• Horizontal Gaze Nystagmus (eye movement tracking)
• Walk-and-Turn
• One-Leg Stand

These tests are voluntary in Nevada, but refusing to perform them can raise further suspicion. Poor performance on these tests gives the officer more evidence to justify a DUI arrest.

Officers are trained to look for specific clues of impairment during FSTs, such as:

• Swaying or using arms for balance
• Starting tests too soon or failing to follow instructions
• Missing heel-to-toe steps
• Stumbling or putting a foot down during balance tests

While these tests aren’t always conclusive, they are widely used to support probable cause. If a driver performs poorly, the next step is typically a preliminary breath test (PBT) or chemical test request.

Field sobriety testing is an important middle step in the DUI arrest process—falling between the initial stop and formal testing. In Nevada, failure of these tests strongly increases the likelihood of arrest.

Preliminary Breath Testing and Chemical Evidence

Once an officer believes there’s sufficient reason to suspect DUI, they may request a breathalyzer or other chemical test to measure the driver’s blood alcohol concentration (BAC). In Nevada, drivers are considered legally impaired if their BAC is 0.08% or higher.

For commercial drivers, the limit is 0.04%. For drivers under 21, Nevada enforces a zero tolerance policy with a BAC threshold of 0.02%.

Chemical testing may include:

• Roadside breath tests (using portable devices)
• Formal breath tests at the station
• Blood draws (especially for suspected drug use)

While roadside tests provide a quick reading, they are often followed by more accurate tests at a facility or medical center. Officers use these test results to further justify the arrest and prepare evidence for potential prosecution.

Refusing a breath or blood test in Nevada can lead to automatic license suspension under implied consent laws, and in some cases, a warrant may be issued to compel testing.

Chemical evidence plays a critical role in DUI arrests. A high BAC level almost always leads to immediate arrest and sets the stage for administrative and criminal proceedings.

Other Circumstances That Can Trigger a DUI Arrest

While most DUI arrests in Nevada follow a predictable pattern—stop, observe, test—some situations trigger arrests more directly. These include:

• DUI checkpoints: Nevada law allows for sobriety checkpoints where drivers may be stopped without specific suspicion. Signs of impairment can lead to immediate testing and arrest.
• Car accidents: If a driver is involved in a crash and suspected of being impaired, officers can initiate a DUI investigation on the spot.
• Driver admission: Voluntarily admitting to drinking or using drugs can be used as part of probable cause to arrest.
• Drug possession: If drugs are found in the vehicle or on the driver, this can escalate an investigation, especially if impairment is suspected.

In some cases, officers may rely on drug recognition experts (DREs) to assess signs of drug impairment. These specialists are trained to identify physical and behavioral clues linked to various substances.

Understanding these additional triggers is important because not all DUI arrests begin with obvious intoxication. The context—such as location, time of day, or recent behavior—can also influence how officers proceed.

The Role of Probable Cause in Nevada DUI Arrests

All DUI arrests in Nevada must be supported by probable cause—a legal standard that requires enough factual evidence to believe a crime has occurred. This prevents arbitrary or unjustified arrests.

Probable cause in a DUI case typically builds step by step:

1. Observable traffic violation or erratic driving
2. Signs of impairment during initial interaction
3. Field sobriety test performance
4. Breath or blood test results

Each of these layers adds to the officer’s case for arrest. If enough evidence is present at any stage, the driver can be arrested and taken into custody for DUI.

In situations where the evidence is weak, the officer may issue a warning or pursue other charges instead. However, once probable cause is met—especially with chemical test confirmation—the arrest is almost certain.

Nevada courts closely examine whether proper procedures were followed in building probable cause. This ensures that arrests are based on real, observable evidence and not subjective judgment alone.

FAQ About DUI Arrest Triggers in Nevada

Do you have to be over the legal BAC limit to be arrested for DUI in Nevada?
No. Even if your BAC is below 0.08%, you can still be arrested if an officer believes you are impaired and not safely able to drive.

Can you refuse a breath test during a Nevada traffic stop?
You can refuse, but doing so may result in immediate license suspension and potentially a warrant for blood testing.

What if you fail a field sobriety test but pass the breathalyzer?
You may still be arrested if the officer believes drugs are involved, or if your behavior strongly suggests impairment.

Are DUI checkpoints legal in Nevada?
Yes. Nevada allows law enforcement to set up sobriety checkpoints, provided certain guidelines are followed.

Can you be arrested for DUI if you’re parked or sleeping in your car?
Yes, in some cases. If the officer believes you were recently driving or intended to drive while impaired, an arrest is possible.

Conclusion

A DUI arrest in Nevada is triggered by a combination of observed behavior, test performance, and chemical evidence. From the initial traffic stop to the moment of arrest, law enforcement officers follow a consistent process to determine if a driver is under the influence. Understanding these steps helps clarify what signs officers rely on and what drivers should expect during a DUI stop.

For a broader look at how Nevada’s impaired driving laws are structured, explore the How DUI Laws Work pillar page. To learn more about the specific signs and procedures used during stops, visit the What Triggers a DUI Arrest During a Traffic Stop mini-hub.