A DUI stop in Las Vegas can unfold quickly, and the decisions made in those moments may determine whether you face a DUI arrest, further testing, or a possible DUI conviction. As Nevada strengthens its enforcement strategies for impaired driving in 2025, law enforcement officers rely on updated protocols, enhanced observation training, and more refined field sobriety tests to identify suspected drunk drivers.

Understanding what Las Vegas police look for during a DUI stop in 2025 is essential for anyone operating a vehicle. Officers are trained to detect subtleties—behaviors, physical cues, and driving patterns—long before they ask a driver to step out of the car. And once the stop begins, everything from the way you answer questions to how you stand can influence the officer’s interpretation of probable cause.

This guide explains exactly what officers evaluate, how standardized field sobriety tests work, and what rights drivers have during a DUI stop. It also shows why contacting a DUI defense attorney immediately may be the most important step you take after an arrest.

How Las Vegas Police Identify Impaired Drivers Before the Traffic Stop

A DUI investigation typically starts before the officer even activates their lights. Las Vegas police scan for erratic driving patterns that suggest possible drunk driving, such as drifting between lanes, inconsistent speed, delayed reaction to traffic signals, sudden braking, or an improper turn. Under Nevada law, these driving behaviors create the reasonable suspicion needed for an officer to initiate a traffic stop.

Once the vehicle is pulled over, the officer begins assessing the driver’s behavior. Fumbling for documents, difficulty maintaining eye contact, or struggling to follow simple instructions may be interpreted as signs of impairment. Even the smell of alcohol or the presence of an open container inside the motor vehicle can escalate the encounter into a full DUI investigation.

Initial Police Conduct During a 2025 Las Vegas DUI Stop

When the officer approaches the window, they look for immediate cues indicating that a person driving may have consumed alcohol or drugs. Indicators such as slurred speech, delayed responses, bloodshot eyes, or difficulty producing a driver’s license can influence the officer’s decision to move the stop into a formal investigation phase.

Officers ask questions designed to gauge cognitive responses. However, drivers are not legally required to answer questions about alcohol consumption. You have the constitutional right to remain silent and avoid self-incriminating statements—something most drivers do not realize during a stressful encounter.

If the officer observes enough factors suggesting impairment, they will request the driver to step out of the vehicle to begin a formal evaluation.

Why Officers Request Field Sobriety Tests During Las Vegas DUI Stops

In 2025, Las Vegas police will continue to use field sobriety tests as a primary tool to determine whether additional chemical testing is warranted. Although the tests are voluntary, officers often create pressure that makes drivers feel they must comply.

The officer looks closely at how the driver exits the vehicle, whether they use the door for balance, and how steadily they stand. Once the driver is in position, the officer proceeds with the standardized field sobriety tests approved by the National Highway Traffic Safety Administration (NHTSA).

These include:

• The Horizontal Gaze Nystagmus test
• The Walk and Turn test
• The One Leg Stand test

Each test has specific clues that officers use to determine impairment. Even slight mistakes—often caused by nerves or uneven surfaces—may be interpreted as evidence of intoxication.

Understanding the Horizontal Gaze Nystagmus Test and What Police Look For

The horizontal gaze nystagmus test is often the first assessment performed. Officers ask drivers to follow a pen or flashlight with their eyes while they look for involuntary jerking. This jerking increases when a person’s blood alcohol concentration rises.

Police officers focus on three elements: smooth pursuit, maximum deviation, and onset of nystagmus before 45 degrees. However, many medical conditions, medications, and fatigue can cause similar eye movements, which is why this test is frequently challenged in a DUI case.

How Las Vegas Officers Evaluate the Walk and Turn Test in 2025

The Walk and Turn test is divided into two phases: the instruction stage and the walking phase. Officers watch how well the driver can follow instructions, maintain balance, and perform heel-to-toe steps along a straight line.

Indicators such as stepping off the line, starting too soon, losing balance, using arms for stability, or making an improper turn are flagged as signs of impairment. Yet many sober drivers struggle due to anxiety, poor shoes, uneven pavement, or physical limitations.

How the One Leg Stand Test Influences DUI Arrest Decisions

During the One Leg Stand test, police instruct the driver to raise one foot about six inches off the ground and count aloud. Officers watch for swaying, hopping, putting the foot down, or struggling to stay balanced.

Interestingly, this test can wrongly suggest impairment due to medical conditions, injuries, weight distribution issues, or even stress. Nevertheless, officers rely heavily on test results to determine whether further testing—such as a breath test or blood test—is required.

Preliminary Breath Tests and Chemical Testing Procedures in Las Vegas

If officers believe there is enough evidence of impaired driving, they may request a preliminary breath test at the scene. While roadside breath tests help determine probable cause, the formal evidentiary breath test or blood test usually occurs after the arrest.

Refusing chemical testing can trigger automatic license consequences because Nevada’s implied consent laws allow officers to obtain a court-ordered blood draw if necessary. The outcome of these tests plays a major role in both the charges filed and the potential for conviction.

How DUI Checkpoints and Blitz Patrols Increase DUI Arrests in 2025

Las Vegas continues to use DUI checkpoints, saturation patrols, and DUI blitz operations to target impaired drivers. During these events, officers focus specifically on detecting driving under the influence, giving them opportunities to observe thousands of vehicles quickly.

Police look for traffic violations, refusal to follow instructions, difficulty stopping, or delayed compliance—any of which can lead to a full DUI investigation.

How Officers Use Probable Cause to Justify a DUI Arrest

Throughout the entire encounter, officers gather observations to establish probable cause. This may include driving behavior, physical signs, speech patterns, odor of alcohol, difficulty performing field sobriety tests, or statements made by the driver.

Once officers believe probable cause exists, they make a formal DUI arrest, and the case begins its journey through the Nevada court system. At this stage, contacting a Las Vegas DUI defense attorney becomes essential to protect your rights.

Why You Should Never Try to Talk Your Way Out of a Las Vegas DUI Stop

Drivers often believe cooperation or explanation will help, but officers are trained to document statements in ways that support the prosecution’s case. Talking too much may unintentionally provide evidence that strengthens the DUI charges. The safest choice is to remain silent and ask to speak with an attorney immediately.

FAQ

What signs of impairment do Las Vegas police look for before starting a DUI investigation?

Officers focus on driving behavior such as drifting, erratic speed, missed traffic signals, and improper turns. Once the stop begins, they evaluate speech, coordination, eye appearance, and ability to follow instructions to determine whether to proceed with field sobriety testing.

Are field sobriety tests required during a Las Vegas DUI stop?

No, field sobriety tests are not legally required. Drivers can decline them, though refusal may lead officers to rely on other observations to determine probable cause. A DUI attorney can review whether the officer properly explained your rights.

What happens if I refuse a breath or blood test during a DUI stop in Nevada?

Nevada’s implied consent laws allow a court-ordered blood draw if you refuse testing. Refusal may also result in automatic license suspension. An attorney can help challenge the legality of the testing process and the officer’s justification.

Conclusion

A DUI stop in Las Vegas can escalate in seconds, especially as Nevada law continues to emphasize strict enforcement in 2025. Police rely on structured observations—driving patterns, physical cues, standardized field sobriety tests, and chemical testing—to determine whether a driver may be impaired. But these assessments are not perfect, and many sober drivers fail them due to nerves, medical issues, or unfair testing conditions.

If you were arrested or accused of impaired driving, remember that a DUI charge is not a conviction. With the right defense strategy, it may be possible to suppress evidence, challenge police conduct, or reduce the consequences you face.
If you’re facing a Las Vegas DUI arrest in 2025, take action now. Reach out to The Defense Firm today for a free consultation with a dedicated Las Vegas DUI defense attorney who will fight to safeguard your rights, your freedom, and your ability to keep driving.