In the U.S., there are two main reasons that the police can take action against someone. They are the standards known as reasonable suspicion and probable cause. While they are similar in their application and definitions, there are several key differences between the two. To make sure that your rights are protected, it is important that you understand the differences between the two. Here is a look at reasonable suspicion vs probable cause.

Reasonable Suspicion

Reasonable suspicion is a concept that police use to justify their attempt to pursue criminals. Reasonable suspicion gives police the right to pursue criminals if the is a credible reason to believe that their efforts will uncover anything related to a crime. When invoked, police have to be able to back up their actions with detailed facts or conclusions that any reasonable officer would consider credible.


Take a brawl at a bar for an example. An officer arrives at the scene of a fight and there are two people that look like they were involved. The officer can detain both of them on the spot since a reasonable officer could determine who was in the fight immediately based on visible evidence. In this case, the officer has reasonable suspicion that these two people were in a fight and can back up that suspicion by clear and reasonable evidence. While this is a starting point for further action, the officer must still collect evidence to make an arrest and file charges.

Probable Cause

Probable cause works in the same way that reasonable suspicion does. Officers must have a credible reason to think that their actions will uncover a crime, and this credible reason must be based on verifiable evidence. It limits the ability of police to act against civilians unless there is a strong to think that a crime has been committed or is being committed at the time. Officers must have probable cause to arrest or take any other action that will lead to criminal charges being filed.

The Key Difference: Levels of Severity

The main difference between probable cause and reasonable suspicion is the level of severity between the two. Reasonable suspicion is the less severe standard and has a lower burden of proof to be used. However, reasonable suspicion, at best, can lead to detaining suspects. It is not a strong enough standard to pursue criminal charges. For the more severe actions like making an arrest or searching someone’s property, officers need probable cause which is based on hard evidence. In short, reasonable suspicion is the less severe standard and probable cause is the more severe standard.

Why They Matter

Reasonable suspicion and probable cause matter because they offer basic protections for civilians. They set standards that police have to meet before they can take action against you. In the case of reasonable suspicion, the standard is relatively low but provides a basic level of protection against an officer doing anything at any time. Probable cause offers a much higher level of protection and is backed by the Fourth Amendment of the U.S. Constitution. It ensures that police must secure warrants for searches and have clearly defined reasons before arresting someone.


When the police invoke reasonable suspicion or probable cause, that means that there has likely been a crime committed. If you are involved in those situations, it is important to know your rights. Police often place a lot of effort into making sure that they are right before taking action, but there are times when their actions or assumptions are incorrect. In those instances, you may want to seek legal help from a qualified attorney.


With 6 years of experience as a Harris County prosecutor and 11 years of experience representing clients in a variety of family, domestic, and criminal cases, past president of the Montgomery County Criminal Defense Lawyers Association, Andrea Kolski, has the background you need to win your case. For more information or to schedule a consultation, call Nonstop Justice today at 832-381-3430.