Reasonable Suspicion of a DUI: How Does It Affect Your Case?

No one likes being pulled over. When you see the blue-and-red lights of a police car in your rearview mirror, it’s normal to feel a little anxious—even if you don’t think you’re doing anything wrong. But what if you’re really not doing anything wrong, and the police pull you over anyway? That’s a violation of your rights. Every driver should know what creates reasonable suspicion of a DUI and what to do if you’re pulled over.

What Is Reasonable Suspicion?

Reasonable suspicion is a legal standard used by law enforcement to justify brief stops and investigations. It means that a police officer has a specific reason to believe that a person may be involved in criminal activity, based on the officer’s observations and experience, and the information available at the time.

If an officer has reasonable suspicion you’re committing a crime, they’re generally allowed to detain you for a limited amount of time in order to further investigate. Reasonable suspicion of a DUI is what allows an officer to pull you over, ask you questions, and look for further evidence to confirm their suspicion. If the officer confirms their suspicion that you’re under the influence, that provides probable cause for an arrest and DUI charges. (We’ll talk about probable cause later.)

Examples of Reasonable Suspicion of a DUI

Drivers who are under the influence often show similar behaviors because of the way alcohol affects the brain. Police officers are trained to identify these behaviors so they can determine if there is reasonable suspicion of a DUI. For example, any of the following behaviors definitely justify a traffic stop:

• Swerving, weaving between lanes, drifting
• Driving in the wrong lane, driving the wrong way on a one-way street
• Driving too slowly for the speed limit
• Stopping too far or short before a stop sign
• Frequent braking or stopping in the road for no apparent reason
• Driving at an irregular speed, accelerating for no reason
• Responding slowly to traffic signals
• Making unsafe lane changes or turns
• Almost hitting another car or an object in the road

You don’t have to be showing these obvious signs of DUI in order to be pulled over. An officer could also pull you over for a standard traffic violation, like having a tail light out or not coming to a full stop at a stop sign. These minor offenses allow them to detain you and give you a traffic ticket—but once you’re pulled over, they might find probable cause to arrest you for a DUI.

Reasonable Suspicion vs. Probable Cause

Making wrong turns, driving too slowly, braking often, and even driving the wrong way down the street don’t necessarily mean you’re under the influence—you could just be lost. The officer can detain you to figure out what’s going on and make sure you can drive safely. They could also give you a traffic ticket. But they can’t arrest you for DUI based on these signs. To arrest you, they need probable cause.

Probable cause is a higher standard and requires more evidence that a crime is being committed. Some examples of probable cause are:

• Smell of alcohol on your breath or in your car
• Presence of alcohol containers in your car
• Flushed face
• Bloodshot or watery eyes
• Slurred speech
• Confused or uncoordinated behavior, like inability to answer basic questions or fumbling with documents
• Admitting to drinking

If the officer notices any of these signs, they’ll ask you to take a standard field sobriety test (SFST) or a breathalyzer. You’re allowed to refuse to take a field sobriety test. You’re also allowed to refuse a breathalyzer, although that has more serious consequences, like automatic license suspension.

While a failed SFST or breathalyzer definitely provides probable cause for the officer to arrest you, keep in mind that you can still be arrested without these pieces of evidence. The officer is allowed to rely on their own observations to make the arrest. In a separate process, the state will decide whether to bring charges against you based on the strength of the evidence. Refusing an SFST or breathalyzer can be used against you in court.

DUI Checkpoints and Reasonable Suspicion

DUI checkpoints are locations where law enforcement officers stop vehicles to check if drivers are under the influence of alcohol or drugs. These checkpoints are typically set up on busy roads or highways during times when impaired driving is more likely, such as weekends, holidays, or late at night. Officers use these checkpoints to randomly stop vehicles according to a predetermined pattern, such as every third or fifth car, to avoid bias.

But wait—doesn’t that mean they’re stopping you without reasonable suspicion of a DUI? Yes, it does. And it’s perfectly legal in most states. As with implied consent, the U.S. Supreme Court has found that the state’s interest in protecting public safety outweighs drivers’ right to privacy in this situation. While some states have outlawed DUI checkpoints, they’re legal in Oklahoma.

At DUI checkpoints, officers briefly interact with drivers to look for signs of impairment, such as the smell of alcohol, slurred speech, or visible intoxication. If a driver shows signs of being under the influence, they may be asked to pull over for further evaluation, like an SFST or breathalyzer. Just like with a regular traffic stop, showing any signs of intoxication, failing an SFST or breathalyzer, or even refusing them, all provide probable cause to arrest you.

How Does Reasonable Suspicion of a DUI Affect Your Case?

Thanks to the U.S. Constitution, citizens have certain inalienable rights, which means they can’t be taken away, even by the state or government. This includes the right to privacy and rights against self-incrimination and unreasonable searches and seizures. As we learned, sometimes the state’s interest in protecting public safety outweighs these rights, like with DUI checkpoints.

However, if you’re not at a checkpoint, the police can’t randomly pull you over without having reasonable suspicion of a DUI or a traffic violation. And they can’t arrest you without probable cause. If you were pulled over or arrested for no reason, your rights were violated and your DUI could be dismissed.

Of course, the police will always say they had reasonable suspicion and probable cause. An experienced attorney will investigate their claims to make sure the arrest and charges are valid, for example by looking at:

• Traffic cameras at intersections
• Patrol car dash cameras
• Police body cameras

If your traffic stop or arrest was invalid, we may be able to suppress the evidence the police collected during that traffic stop. That could include the officer’s observations and your SFST, breathalyzer, or blood test results. And that will probably weaken the state’s case enough to get your DUI dismissed.

The Bottom Line

You don’t have to be charged with a DUI to care about your rights. At the Oklahoma DUI Guy, we believe that every driver needs to be aware of their rights on the road. But if you’re pulled over on suspicion of a DUI, it’s especially important to know what you can do—and how it could affect your case. Even if you’re arrested, remember that your case isn’t over yet. Hiring an experienced DUI attorney can make a big difference in the outcome. Contact the Oklahoma DUI Guy today for a free case evaluation to see how we can help you.