From Clues to Convictions: Unlocking the Power of Probable Cause

What Constitutes Probable Cause?

Our protection against unlawful arrests and unreasonable searches and seizures is one of the things that makes America great. It is a fundamental right that the founders wanted to safeguard after their experiences with the British during the American Revolution.

Law enforcement must show a judge that a crime is being committed, or is about to be, in order to obtain a search or arrest warrant (probable cause). The Fourth Amendment prevents law enforcement from unwarranted searches, seizures, arrests, and detentions. The police must follow these standards so that the evidence collected from the search will not become inadmissible or the charges be thrown out of court.

A skilled attorney helps you to understand probable cause and how it relates to your case. We give you objective advice and will use it to strengthen your case.

The attorneys at Wolfe & Stec have handled hundreds of criminal cases, and we use our decades of experience to protect you. Criminal investigations and charges are serious crimes, and you need a skilled attorney to advise and guide you.

What Constitutes Probable Cause?

Showing probable cause requires proving more than a suspicion that a crime is being committed. It entails showing evidence that a crime is happening or will occur. There are several ways this can be demonstrated:

Law enforcement observations: If a police officer observes illegal activity firsthand (such as witnessing a crime), this is considered to be probable cause.

Using reliable sources: Reliable sources are victims, witnesses, and credible informants.

Physical evidence: Any tangible evidence linking the suspect to the crime is probable cause, including surveillance footage, fingerprints, and DNA.

Sworn statements: Sworn statements could be obtained from credible witnesses that a crime is occurring.

These are some of the ways probable cause is established before a judge. The judge will review the evidence and decide if it is enough to issue a search or arrest warrant.

What is Probable Cause?

Probable cause requires showing a reasonable belief that a crime is being committed or is about to occur. It uses evidence to support law enforcement’s suspicions using different sources. The police use the evidence to arrest someone or obtain a search warrant to enter the location and look for further evidence of a crime.

It is established by considering the total circumstances using the evidence, including evaluating the credibility of information and collective weight. Probable cause begins when the arrest or search warrant is issued and cannot be used retroactively.

The courts play a crucial role in reviewing whether probable cause exists and where it is lacking. These standards are used to decide if an arrest, search, and the evidence collected are lawful.

A skilled attorney can help you determine whether probable cause existed when your property was searched or you were arrested. Our team of litigators has decades of experience handling these cases, and we will give you objective advice about whether there was a possible breach of these standards. Probable cause is complex, and you need someone who knows the law that can make compelling arguments for you.


ARRESTS — The Fourth Amendment requires that any arrest be based on probable cause, even when the arrest comes before getting a warrant. If there is a lack of probable cause, a warrantless arrest becomes invalid, and any evidence resulting from that arrest (such as confessions or drugs found) is not admissible. An exception may be that the arresting officer, as a result of a mistake by court employees, mistakenly and in good faith believes that a warrant has been issued.

SEARCH WARRANTS — Probable cause exists to get a search warrant when there is a good chance the search will result in evidence of a crime being discovered. There must be an affidavit or recorded testimony to support the warrant by explaining on what basis probable cause exists. Since it is presumed that police officers are reliable sources of information, affidavits will often include their observations. If a search is done without a warrant, in-court testimony can establish probable cause later.

DIGITAL PROBABLE CAUSE — The digital age and searching data and devices complicate the probable cause. In Riley v. California (2014), the Supreme Court ruled that police generally may not search digital information on an arrested person’s cellphone unless there is a warrant. However, there are new cases due to be heard about seizing information from phone companies that will impact the ability of data companies to share user information with law enforcement.


Reasonable suspicion is not used in allowing or conducting searches. It allows a police officer to stop and detain a person briefly if, in the officer’s trained opinion, there is reason to believe the person is engaging or has engaged in criminal activity. Reasonable suspicion uses the standard of a “reasonable law enforcement officer” who learns facts that would lead a rational person to believe that the individual has committed a crime. The officer uses this to establish probable cause to arrest an individual or request a search warrant.

What is the Interpreted Meaning of Probable Cause?

The interpreted meaning of probable cause refers to the legal standard deciding whether sufficient evidence exists to support the view that a crime is being committed. It balances individual rights and interests against law enforcement to prevent unreasonable searches, seizures, arrests, and detentions.

The definition of probable cause continually evolves through case precedent and court decisions. Here are some critical elements of the interpreted meaning of probable cause.

Reasonable belief: Probable cause uses reasonable assumptions based on facts and evidence, as opposed to opinions or speculation. It follows the standard that a rational person would believe if they were looking at all the information under similar circumstances.

Facts and circumstance: Probable cause requires sufficient evidence to support the theories of law enforcement to issue the arrest or search warrant. They have to show proof of the crime being or about to be committed.

The totality of circumstances: A judge reviews all the available information (the totality of circumstances) to decide if the evidence is sufficient for a warrant.

Objectiveness: The standard for probable cause is what a reasonable person would use to support the theories of law enforcement.

Probable cause requires showing clear proof before getting the arrest or search warrant. A skilled attorney will analyze whether probable cause existed before your arrest or search and review the options. Our team has decades of experience working on these cases, and we will look out for you.

Attorney Marc Wolfe

Marc Wolfe has been representing clients in criminal matters in Chicago and the entire State of Illinois for over 30 years. Mr. Wolfe has tried over 300 cases to verdict and represents clients facing investigation or prosecution for a broad range of state and federal criminal offenses, including murder, embezzlement, sexual abuse, drugs, marijuana and white collar crimes. [ Attorney Bio ]