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Probable cause has historically been used as a standard for conducting searches and seizures, including arrests. The exact probable cause definition varies by jurisdiction, but probable cause generally means that there is a substantial possibility or probability that an individual has committed or will commit an offense.

But, what is the exact definition of probable cause?

Table of Contents (click to jump to a specific section)


What is “Probable Cause”?

The legal basis for arrest, search, or seizure of property is “probable cause.” The Fourth Amendment of the United States Constitution reads:

“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be searched.”

In order for a court to issue a warrant, there must be evidence of probable cause. Probable cause is defined and examined in this paper in connection with detention, arrest, search, seizure, and prosecution. But, should a probable cause always be required to obtain a search warrant?

Probable Cause And Warrants

An officer signs an affidavit affirming the facts they know from their own observations or the observations of citizens or police informants in order to get a warrant. These facts, according to them, provide evidence that there is probable cause for a search, seizure, or arrest.

If a court or magistrate is satisfied that there’s enough evidence to support probable cause based on the totality of the circumstances, they’ll issue an arrest or search warrant. The judge is counting on the police officer’s honesty in providing accurate information. There are no allegations to defend against.

In certain circumstances, such as when arrests are based on personally observed conduct, warrants are not required. If a warrantless arrest does happen, the defense may mount a legal challenge against it in a court hearing.

When Search Warrants Aren’t Always Required:

Reasonable Suspicion Vs. Probable Cause

A police officer may have reasonable cause to suspect that a crime is being committed if all of the facts and circumstances of the scenario suggest that a reasonable police officer would as well.

The police officer does not need actual evidence to have reasonable suspicion. Rather, the presumption of reasonable suspicion is based on the officer’s training, the circumstances of the occurrence, and what other officers would do in similar situations.

If a police officer has reasonable suspicion to suspect something is wrong with you, he or she may briefly detain you while investigating further, but an arrest may not be made based on reasonable suspicion alone. For example, if a motorist is driving erratically, switching between lanes, and failing to stop for traffic signals, a police officer may have reasonable suspicion that the driver is intoxicated.

The officer may stop the vehicle, but the officer does not have to arrest the driver unless there is further evidence of drunk driving to create reasonable suspicion for an arrest. If a motorist flunked a sobriety test after being stopped, this might be sufficient probable cause for an officer to make a drunk driving charge.

Of course, there are times when an officer believes they have probable cause while they do not.


Uses of Probable Cause That Are Illegal


The cops cannot just pull anyone over on the road. Before making a traffic stop, police regulations demand that an officer have reasonable grounds to believe that a violation has occurred.

If an officer suspects a motorist of driving while intoxicated based on erratic lane changes, excessive speeds, and unpredictable braking or running red lights, for example, he or she may have sufficient cause to stop the vehicle under suspicion of DUI.

If the motorist was staying in his lane and driving at reasonable speeds, the officer would have no cause to pull him over, and any accusations against him might be thrown out based on an improper traffic stop. This is a valid defense in DUI cases where police officers used field sobriety tests without reasonable cause.

In two situations, police can arrest individuals: when they observe someone commit a crime and when they have an arrest warrant. A police officer may lawfully arrest someone if she sees that person run out of a business with a handful of cash and a gun.

If the officer reaches the site of the robbery after it has occurred and only has witness testimonies to go on, they will need to undertake a comprehensive investigation before making an arrest. They must also contact a district attorney to petition a court for an arrest warrant. Only after obtaining an arrest warrant can they go ahead and apprehend the designated culprit.

A warrantless arrest is not foolproof. The name of the suspect, the charges he or she is facing, the amount of bail sought for those charges, which court issued the warrant, when it was issued, and a judge’s signature are all required components of an arrest warrant.

If there is any information that isn’t included, the warrant might be invalid. In addition, police officers must have probable cause to issue an arrest warrant. The arrest warrant can be rendered invalid if the probable cause was based on false facts or lies.

Searches, seizures, and arrests are based on probable cause. An officer may only search a home or vehicle if there is sufficient cause to believe a criminal act has occurred, and in some instances, search warrants must be obtained, which are also justified on the basis of probable cause.

For instance, if an officer looks through a truck’s window and sees a brick of heroin, he or she has probable cause to search the vehicle because of the “plain view” doctrine.

The minor doctrine allows the officer to search a vehicle without requiring strong probable cause, such as the presence of a controlled substance detected by a K9. Otherwise, a search warrant would be necessary. If an officer collects evidence as a result of an illegal search and seizure, that evidence may be ruled inadmissible in a trial and the case may be dismissed.

The Miranda Rights are some of the most robust safeguards available to someone being detained. They ensure you have the right to silence, counsel, and the understanding that anything you say may be used against you in court.

Police must read all defendants their Miranda rights, and once a defendant has done so, officers must comply with those provisions. Minors under the age of 16 also have additional defenses. Minors 15 years old or younger can only waive their Miranda Rights after consulting with a lawyer, for example.

It may be a breach of due process if an officer fails to inform a defendant of his or her rights under Miranda.

Probable Cause and Kirakosian Law

If you feel that your rights have been violated due to an illegal use of “probable cause”, talk to an attorney as soon as possible. At Kirakosian Law, we stand up to government entities when there’s evidence of misconduct by our civic leaders and members of law enforcement. We have no problem taking cases to federal court.

And if we can’t reach an appropriate settlement through mediation, we are fully prepared to take civil cases to trial. We handle civil rights cases, including:

If you or someone you know has suffered emotional distress or injury due to a civil rights violation, contact our attorney at Kirakosian Law APC for a free consultation.