The Importance of Probable Cause in Arrests

The Fourth Amendment requires the police to have probable cause before they can make an arrest, search, or obtain a warrant. But what exactly does probable cause mean? The term is defined by the courts as a basis for a reasonable person to believe that a crime has been committed, which enables the police to make an arrest, or that evidence of a crime is present in a specific location, enabling police to obtain a search warrant.

Defining Probable Cause

The Supreme Court has defined probable cause as a “factual and practical consideration of everyday life on which reasonable and prudent men act.” It means there must be good reasons for a reasonable person to believe that a particular person was involved in a crime. Based on this standard, police officers who can show probable cause can make an arrest without a warrant. However, prosecutors must quickly establish probable cause for the arrest after such an arrest.

Impact of Probable Cause on Arrests

If the police do not have probable cause, they cannot obtain a warrant to make an arrest or search. If they make an arrest on the street without probable cause, the court can dismiss that arrest at the hearing during which the prosecution must show that probable cause existed to make the arrest. Prosecutors must show that the police officers reasonably believed, based on credible evidence, that the person arrested was involved in a crime. If the prosecution fails to show that probable cause existed at the time of an arrest, the arrest will be dismissed.

Exclusionary Rule

If an arrest is invalid for lack of probable cause, any evidence gathered as a result of that arrest is also invalid. Known as the exclusionary rule, evidence gathered in the absence of probable cause cannot be used in the prosecution of an alleged crime. Often, the exclusion of such evidence leads to the dropping of charges.

Probable Cause in the Real World

Probable cause does not mean that the police have to see a crime happening. It can take many forms, such as evidence of a crime in plain sight of the public, the smell of drugs surrounding a suspect, or admissions of guilt. The police officer could make an arrest and conduct a search, even without a warrant, because the officer would be able to show sufficient probable cause to support a warrant after the arrest.

Categories of Evidence for Probable Cause

There are four broad categories of evidence that can establish probable cause. Observational evidence consists of what the police officer sees, smells, or hears. Circumstantial evidence consists of a compilation of facts and circumstances that make it appear that a crime has been committed. Expertise evidence is relevant when an officer recognizes something, such as scratch marks on a doorway indicating that a lock was pried open or picked. Finally, information from confidential informants or members of the public who call in with tips can form the basis of probable cause.

Refusing Consent to a Search

Consent will override the need for probable cause. For instance, most traffic violations are not considered probable cause. During a stop for a traffic violation, police can search a vehicle if they have probable cause. But if minor traffic violations are not probable cause, how do the police get to search a car? By asking for consent. If the police are asking for permission to search, they do not have probable cause. People always have the right to refuse to allow a search not based on probable cause. Once someone consents to a search, the police do not need probable cause, but if they search without consent, anything they find should not be admissible as evidence.

If you have been arrested, it is important to contact an experienced criminal attorney. The attorneys at Scott Kent P.A. have extensive experience as both prosecutors and defense attorneys. They are committed to delivering the best possible result for their clients. For a consultation in DuPage, Kane, or Cook County, contact them 24 hours a day at (630) 474-8000.