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Elements of a Las Vegas DUI - Probable Cause for Alcohol DUI

Elements of a Las Vegas DUI - Probable Cause for Alcohol DUI

An arrest for a Las Vegas DUI requires probable cause. However, the probable cause that leads to an arrest for a DUI in Las Vegas is almost always secondary. Generally, something that prompts a stop - such as weaving, a car stopped in the road, an accident, etc. - leads to an officer stopping and investigating. An officer may seize an individual for investigation without probable cause but still needs reasonable suspicion. How you interact with the officer after this initial stop can lead to reasonable suspicion shifting to suspicion of a DUI. If there is enough evidence, the officer will have probable cause to arrest you. In this article, we'll be discussing how reasonable suspicion and probable cause can affect your DUI case. We'll be talking about the following:

  • Reasonable Suspicion and Probable Cause - What are they?
  • Reasonable Suspicion for a stop
  • Probable Cause for a Las Vegas DUI

Reasonable Suspicion and Probable Cause in Las Vegas, Nevada - What are they?

Reasonable suspicion and probable cause in the legal world are terms of art. A term of art means that there is no hard and fast definition. They are both prerequisites for an arrest, but it is very much a "you'll know it when you see it." We'll first turn to reasonable suspicion since that is what generally prompts a stop. Next, we'll look at probable cause.

Reasonable Suspicion - Definition

Reasonable suspicion is a standard in the law that allows an officer to stop somebody if they have a suspicion that an individual was, is, or is about to commit a crime. It must be more than a hunch, and officers must articulate their reasoning for the stop. The Nevada Supreme Court defined it in State v. Rincon:

Reasonable suspicion is not a stringent standard, but it does require something more than a police officer's hunch. A law enforcement officer has a reasonable suspicion justifying an investigative stop if there are specific, articulable facts supporting an inference of criminal activity.

In the context of a Las Vegas DUI stop, officers must identify driving patterns or behavior that led to the traffic stop of the person driving the car. For example, if somebody is driving slowly and having trouble maintaining their lane, or if a car is not moving at a green light. These are acceptable indicia of intoxication that can lead to an officer stopping an individual to conduct an investigation. Officers CANNOT stop an individual to check for intoxication simply because they want to.

Probable Cause - Definition

Probable cause is a necessary prerequisite to an arrest. Officers might jump over reasonable suspicion if they witnessed a crime because they have probable cause to arrest you. Probable cause is also a bit difficult to define. The best way is to look at the definitions. Here is the definition of probable cause from the Bouvier Law Dictionary:

The reasonable basis for suspicion of a crime or evidence of a crime. Probable cause is the whole set of facts and conditions that form a reasonable basis for a reasonable police officer to suspect a crime has been committed, a person has committed it, or there is evidence of it in a given place at a given time.

The Nevada Supreme Court has also established a definition of probable cause, albeit much shorter. In Sheriff, Washoe Cty. v. Hodes, from 1980:

The finding of probable cause may be based on slight, even "marginal" evidence because it does not involve a determination of the guilt or innocence of an accused.

From these two definitions, we can understand what constitutes probable cause for a Las Vegas DUI arrest. There must be slight or marginal evidence that you were in actual physical control of your vehicle while over .08 or at a point where you could not safely operate the vehicle.

We're now going to look at how the two interact to lead to an arrest for DUI in Las Vegas.

Reasonable Suspicion for a Las Vegas DUI

Reasonable suspicion can come from various behaviors displayed by somebody operating a motor vehicle. The National Highway Traffic Safety Administration has identified four categories to use as cues for impaired drivers. There is a total of 24 cues throughout the categories. Observing certain behavior predicts impairment with a percentage chance of impairment. Here are the cues and their percentages of impairment:

  1. Problems in maintaining proper lane position - 50% - 75% chance of impairment.
    1. Weaving - a vehicle is moving toward one side of the lane and then the other.
    2. Weaving across lane lines - a vehicle is drifting across the lane line, then correcting back towards the other side of the lane and repeating.
    3. Straddling a lane line - a vehicle moves straight ahead with either the right or left tires on the wrong side of the lane line.
    4. Drifting - A vehicle moves in a generally straight line but at a slight angle to the lane.
    5. Swerve - A vehicle makes an abrupt turn away from a generally straight course when the driver realizes that they have drifted out of proper lane position.
    6. Almost striking someone or something - A vehicle in the traffic flow or moving slowly passes unusually close to another driver, a sign, barrier, building, or other objects. 
    7. Turning with a wide radius or drifting during a curve - A vehicle appears to drift to the outside of the lane or into another lane through the curve or while turning a corner.
  2. Speed and Braking Problems - 45% - 70% chance of impairment.
    1. Stopping Problems - Stopping too far from a curb or at an inappropriate angle; stopping too short or beyond a limit line; jerky or abrupt stops
    2. Accelerate or decelerate rapidly for no apparent reason.
    3. Vary speed, alternating between speeding up and slowing down.
    4. Be driven at a speed that is 10 miler per hour or more under the limit.
  3. Vigilance Problems - 55% - 65% chance of impairment.
    1. Driving in opposing lanes or the wrong way on one-way roads.
    2. Slow response to traffic signals.
    3. Slow or failure to respond to officer's signals.
    4. Stopping in the lane for no apparent reason.
    5. Driving without headlights at night.
    6. Failure to signal or signal inconsistent with action.
  4. Judgment Problems - 35% - 90% chance of impairment.
    1. Following too closely.
    2. Improper or unsafe lane change.
    3. Illegal or improper turn.
    4. Driving off the roadway.
    5. Stopping inappropriately in response to an officer's signal.
    6. Inappropriate or unusual behavior - arguing with other drivers, throwing things, etc.
    7. Appearing to be impaired.

Often officers will look for one or two clues together. If a driver displays multiple cues, it will almost always result in a stop to check for impairment. It is important to note that the Nevada Supreme Court has singled out slow driving by itself as not sufficient to justify a stop. Drivers must display more than just one cue if the only cue is driving slowly.

Many of these behaviors can also be linked to several other reasons. For example, eating, texting, or talking animatedly while driving. That doesn't mean an officer can't stop, or it can't lead to a DUI arrest. For example, if you have been drinking but are driving fine, then look down at your phone to see where you are going and swerve out of your lane an officer will be found justified for stopping because you are displaying impairment cues even though it was not the impairment that led to the driving behavior. 

Probable Cause for a Las Vegas DUI Arrest

Once a stop has occurred, officers need probable cause to justify a DUI arrest in Las Vegas. Probable cause is based on the totality of the circumstances. That means that an officer looks at several different cues to determine if there is probable cause to arrest you for a DUI. These cues can be split into two categories: post-stop cues and the Standardized Field Sobriety Test. 

Post-Stop Cues

When an officer stops a driver, they immediately begin assessing a driver's level of impairment even if there are no cues yet! An example is being stopped for speeding. Speeding happens all the time, and the great majority of them are not DUIs. So officers look at the post-stop cues to determine if an investigation needs to be done. Here are several post-stop cues officers are looking for:

  • Difficulty with motor vehicle controls, such as turning lights on or off when trying to turn the car off.
  • Difficulty exiting the vehicle.
  • Fumbling with driver's license or registration.
  • Repeating questions or comments.
  • Swaying, unsteady, or balance problems.
  • Leaning on the vehicle or other object.
  • Slurred speech.
  • Slow to respond to officer or officer must repeat themselves several times.
  • Providing incorrect information, changing answers to questions already asked.
  • The odor of alcoholic beverages from the driver.

It's important to note that officers will often give commands and ask questions immediately after. This is to test impairment since people who are impaired often have trouble multi-tasking. For example, officers will ask for driver's license and registration while also hitting them with a barrage of questions about where they were, if they have been drinking, etc. They are looking to identify the above cues to determine intoxication. If they identify any of these cues, they will then move on to the standardized field sobriety test.

Standardized Field Sobriety Test Cues

The Federal government and prosecutors hail the Standardized Field Sobriety Test (SFST) as the "gold standard" of impairment detection. We'll leave beside the problems in the SFST and how it is administered for now and instead focus on what officers are looking for to secure the probable cause for a Las Vegas DUI arrest.

The SFST is composed of three tests that are used to predict impairment. Those three tests are the Horizontal Gaze Nystagmus, the Walk and Turn, and the One-Legged Stand. 

  1. Horizontal Gaze Nystagmus (HGN): This is an involuntary jerking of the eyes as they gaze toward the side. It is often the most accurate predictor of impairment, but it must be done exactly right. There are six clues for the HGN, with three for each eye. Officers look for the following clues when conducting the HGN:
    1. Lack of smooth pursuit - The eyes are observed jerking or bouncing as they follow a smoothly moving stimulus, such as a pencil or penlight.
    2. Distinct and sustained nystagmus at maximum deviation - The eye is involuntarily jerking or moving when the eye is held at maximum deviation for a minimum of four seconds.
    3. The onset of nystagmus before 45 degrees - When the eye begins jerking before the 45 degrees needed for the distinct and sustained nystagmus.
  2. Walk and Turn (WAT): The Walk and Turn test has a total of eight clues over two stages. The two stages are the instructional stage and the walking stage. 
    1. Can't Balance During Instructions - Instructional phase.
    2. Starts too soon - Instructional phase.
    3. Stops while walking - Walking phase.
    4. Doesn't touch heel to toe - Walking phase.
    5. Steps off the line - Walking phase.
    6. Uses arms for balance - Walking phase.
    7. Improper Turn/Loses balance on the turn - Walking phase.
    8. The wrong number of steps - Walking phase.
  3. One-leg Stand (OLS): The one-leg stand test has only four clues. 
    1. Swaying
    2. Using arms for balance
    3. Hops
    4. Putting foot down

At the end of the field sobriety test, officers will often ask if you will blow into a breath test that officers carry on them. This is called the preliminary breath test and supports a finding of probable cause or could give probable cause if the SFST is not conclusive. In Las Vegas, Nevada, failing to submit to the preliminary breath test will result in the loss of your license for one year under Nevada's implied consent laws.

Once the SFSTs and a preliminary breath test are completed, officers will arrest you for a DUI or release you. If you were arrested for a Las Vegas DUI, you need to contact Las Vegas DUI attorney Charles Goodwin. There are several ways to attack the SFSTs and driving cues. A Las Vegas DUI lawyer is necessary.

A DUI Lawyer is Necessary

Probable cause is a sticky subject. There are several times where it might feel like there was probable cause but there actually wasn't. When you're arrested for a Las Vegas DUI, you need to contact an attorney immediately. Only a DUI lawyer is really equipped to handle these types of cases because they are so fact-dependent. Las Vegas DUI attorney Charles Goodwin knows how to spot the problems with probable cause in DUI cases. If you are being charged with a DUI, contact Goodwin Law Group, PLLC, and DUI attorney Charles Goodwin today.  

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