Skip to content

Probable Cause vs. Reasonable Suspicion – What Is the Difference?

If you are stopped and briefly detained by a law enforcement officer, have your person or property searched by an officer, or are arrested, two important concepts in Pennsylvania’s criminal laws will be at play. Reasonable suspicion and probable cause are two different legal standards that law enforcement officers must meet when they engage in varying degrees of investigation. Officers rely on reasonable suspicion or probable cause to determine whether to stop you for questioning, conduct searches and seizures, or make arrests. If you are facing criminal charges, these concepts might be important. An experienced criminal defense attorney in West Chester, PA at DiCindio Law can review your case to determine whether the officers involved in your case conducted their stops, searches, and seizures properly.

The Supreme Court of the United States established the standards for what constitutes reasonable suspicion and probable cause. While these legal principles are similar, they are also distinguishable. Here is some information to help you understand these concepts and the differences between them.

Understanding reasonable suspicion

Before an officer can stop you and briefly detain you for questioning, he or she must have reasonable suspicion that you have committed a traffic offense or criminal violation. An officer cannot arbitrarily decide to stop people at random who have not committed any offenses. Officers are also prohibited from stopping and detaining people based on inarticulable hunches or because of things like racial profiling.

The Supreme Court set the standards for reasonable suspicion in 1968, ruling that police officers can detain people when they have reasonable suspicion that they are engaged in criminal conduct, have committed criminal offenses, or are preparing to commit crimes. For example, an officer can stop your car if you violate a traffic law. However, an officer may not stop your vehicle simply because he or she thinks you look suspicious when you have not violated any laws. While reasonable suspicion is fairly subjective, a stop cannot be based on hunches and must be informed by the circumstances and facts.

An officer can develop reasonable suspicion based on his or her experiences and training as a law enforcement officer and his or her direct observations of someone else. For example, if an officer witnesses you walking unsteadily from a bar to your vehicle and then sees you weaving as you pull out onto the street, he or she can pull you over based on reasonable suspicion that you might be intoxicated. He or she cannot arrest you until he or she establishes probable cause after your stop to believe that you are driving while impaired, however.

Defining probable cause

Probable cause is a higher standard than reasonable suspicion and is the standard required before police can receive search warrants to search property or seize evidence. Police officers must also have probable cause to believe you committed a crime before they can place you under arrest.

In the previous example, the officer who pulled you over based on reasonable suspicion that you might be driving impaired must conduct a further investigation before arresting you for a DUI. When the officer walks up to the window of your car, he or she will start observing you to look for signs of intoxication. For example, if the officer smells the odor of alcohol on your breath, observes that your eyes are bloodshot or watery, hears that your speech is slurred, or sees empty alcohol bottles in your vehicle, the officer might have sufficient probable cause to arrest you for a DUI.Probable Cause vs. Reasonable Suspicion – What Is the Difference? An officer will also have to have probable cause to secure a search warrant. Officers submit affidavits to judges to request warrants. The judges review the affidavits to determine whether sufficient evidence exists to support a probable cause finding. If the judge believes that the affidavit demonstrates enough probable cause to search your property, the judge will issue a search warrant with defined parameters for the areas to be searched and the types of evidence to be seized. Officers are not allowed to search beyond the areas allowed in the search warrant or to seize unrelated items other than the types of evidence they are searching for.

Why reasonable suspicion and probable cause are important concepts to know

Pennsylvanians are protected against unlawful stops, searches, and seizures under the Fourth Amendment of the U.S. Constitution and Pennsylvania’s state laws. While officers are expected to respect the constitutional rights of the people with whom they interact, some fail to do so.

If an officer stops your vehicle without reasonable suspicion, your criminal defense lawyer can file a motion to challenge your stop. If the judge agrees that the officer did not have reasonable suspicion to stop your vehicle, the stop will be suppressed. Any evidence the officer subsequently seized after your stop will also be declared inadmissible. This would likely mean that the prosecutor would have no choice other than to dismiss the case against you.

Similarly, if you were arrested for a DUI when the officer did not have probable cause to believe that you were driving drunk, your attorney can file a motion to challenge your arrest. Any evidence subsequently obtained after your arrest would be suppressed if the court grants your attorney’s motion. In the case of a DUI, this could mean that your breath test or blood test result could be declared inadmissible in the case against you, greatly weakening the prosecutor’s case.

Get help from DiCindio Law

If you are facing criminal charges, retaining an attorney is important. At DiCindio Law, we can carefully review the stop, search, seizure, and arrest in your case and challenge them if they were not completed properly. Contact us today to schedule an appointment by calling 610-430-3535.

Contact us

  • This field is for validation purposes and should be left unchanged.

Michael DiCindio

Ready To Discuss Your Case?

Recent Articles