What is Probable Cause?

Probable cause is a legal term that is often misunderstood. Law enforcement must have probable cause to believe you committed a crime before they search or arrest someone. 

Probable cause is a particular and reasonable belief that an individual is: 

  • committing a crime, 
  • has committed a crime, or
  • is about to commit a crime. 

Probable cause relies on the information and evidence law enforcement has about a suspect. Arrests are only legal when there is probable cause of a crime. Without probable cause, criminal charges cannot be brought. 

Probable cause can also be the basis for a search warrant. If law enforcement has probable cause to believe you committed a crime, they can ask a judge to authorize a search warrant for your property. However, police do not necessarily need a warrant to search you or your property if they have probable cause to suspect criminal activity.

An example of a warrant exception is “plain sight.” If an officer sees illegal activity in plain sight, then the officer doesn’t need a search warrant to search the person involved.  

What is the Difference Between Reasonable Suspicion and Probable Cause?

Reasonable suspicion is a level below probable cause. If an officer has reasonable suspicion that an individual has committed or is about to commit a crime, then the officer can stop, frisk, and even detain that individual. This is known as a Terry stop, based on the landmark case of Terry v. Ohio

The Supreme Court defined reasonable suspicion as, “the sort of common-sense conclusion about human behavior upon which practical people are entitled to rely.” This means that an officer can make determinations based on how someone is behaving to decide whether they may be hiding evidence of a crime.

Reasonable suspicion can often lead to probable cause. An officer cannot arrest someone based on reasonable suspicion alone. 

How Do Police Officers Establish Probable Cause?

Police officers have several ways they can establish probable cause of a crime. Police can rely on eyewitnesses, confidential informants, and their own perceptions and experience. Probable cause requires an officer to point to specific facts that lead them to believe that the suspect committed or is about to commit a crime. 

If probable cause is established, then it can lead to criminal charges. Probable cause is often debated and challenged by criminal defense attorneys when police overstep their limits.  

Why is Probable Cause Important? 

Probable cause is important because it is the backbone of any criminal arrest. Probable cause allows police officers to make arrests with or without an arrest warrant, depending on the circumstances. When an officer believes they have enough information about suspected criminal activity, they can take that to the judge for an arrest warrant. 

If the judge agrees that there is enough probable cause, they will sign off on a warrant. The officer then uses this warrant to arrest the suspected criminal. Sometimes, an officer may make an arrest without a signed warrant if they believe they have probable cause but don’t have the time or ability to seek a warrant.

Who Determines if There Was Probable Cause in a Case? 

Judges are the final word on whether probable cause exists in a given case. While the police may have based an arrest on what they thought was probable cause, a judge can overrule that determination. If this happens, then the case can be dismissed. 

Defendants can challenge probable cause on factual and legal grounds. If an officer acted outside the law or violated an individual’s Constitutional rights during an investigation, then any evidence that the police officer found suppressed. A judge’s ruling on probable cause can also be appealed to higher courts, all the way to the Supreme Court.

Make Sure to Speak to an Attorney if You Have Been Accused of a Crime

If you have been accused of a crime, it is important that you speak to an experienced criminal defense attorney immediately. If law enforcement did not have probable cause to arrest or search you, a criminal defense lawyer may be able to get your charges dismissed.