Reasonable suspicion Vs. Probable Cause

Reasonable suspicion Vs. Probable Cause

In criminal cases, two legal principles can make all the difference—Probable cause and reasonable suspicion.

When it comes to reasonable suspicion vs. probable cause,  probable cause relies on what could be the objective of the crime and also circumstances and evidence. In contrast, reasonable suspicion is an inclination of the leading agencies to a particular thought related to the incident rather than evidence.

The standards for a criminal offense being a reasonable suspicion or a probable cause were established by the U.S. Supreme Court; while these concepts share similarities, they even have some key differences.

What is reasonable suspicion?

Reasonable suspicion could also be a generally used term in law enforcement. It’s reasonable suspicion when it’s not just a mere thought and a criminal offense committed but less than probable cause. It refers to what a sensible person, or a standard, average person, would consider suspicious. 

Like probable cause, reasonable suspicion is subjective to an enforcement officer’s discretion. Once established, it allows an enforcement officer to carry someone briefly and pat them down.

During a 1968 case, the Supreme Court set parameters for reasonable suspicion. The court stated that enforcement officers could imprison an individual based on the officer’s appropriate training and knowledge and if there is a doubt that a person has committed an offense, is currently engaged in or is getting to commit a criminal offense.

For example, if an official in a patrol car notices a driver swerving recklessly on the road with his headlights turned off while driving in the dark. The officer has reasonable suspicion to pull that person over for a suspected DUI supported by direct observations, training, and knowledge.

What is a Probable cause?

The Fourth Constitutional Amendment guarantees U.S. citizens the right to freedom from unreasonable search and seizure, and an inquiry warrant cannot get issued without evidence.

Although the Fourth Amendment does not define probable cause. In 1949, the Supreme court of the US-led that “probable cause lives where the circumstances and facts are within the officer’s knowledge and of which they have dependable information, which is acceptable for themselves to affirm a belief by an individual of reasonable caution that a criminal offense is being executed.”

The police need evidence to search for your person or property or issue a warrant for an arrest. 

In the example above, the officer has evidence to arrest him for DUI; if the one pulled over on suspicion of DUI, there’s a smell of alcohol, and the person caught slurs his words and speak incoherently.

The probable cause goes beyond reasonable suspicion and gives officers grounds for obtaining search warrants carrying out searches, and making arrests. To achieve the threshold of probable cause, officers must show hard evidence that a criminal offense has been, is being, or is near to take place. For probable cause to be legal, an official must state the facts and evidence to prove the commitment of a criminal act.

What are the key differences between them?

Reasonable suspicion allows a police officer to detain a person who may be committing a criminal offense, has already committed a crime or is planning to commit one. However, it doesn’t allow the officer to look at that individual’s personality, his vehicle, or his home to make an arrest or to search and seize evidence.

The critical difference between probable cause and reasonable suspicion is the level of severity between the two. 

Reasonable suspicion is a less stringent standard that features a lower burden of proof to be used. But, reasonable cause, at best, can cause detaining suspects.

For the more severe actions like arresting or searching someone’s property, officers need Probable cause found on hard evidence.

Hence, reasonable suspicion is the less strict measure, and probable cause is the more severe standard.

Importance of reasonable suspicion vs probable cause

Reasonable suspicion and probable cause matter because they provide basic protections for the citizens. They set standards that police should meet before taking any action. 

In the case of reasonable suspicion, the quality is relatively low, but it gives you a basic level of protection against an official doing anything at any time. 

Probable cause offers greater protection and is laid down by the Fourth Amendment of the U.S. Constitution. So police must secure warrants for searches and have a clearly defined reason before arresting someone.

When the police invoke reasonable suspicion or evidence, a criminal offense has likely been committed. 

If you’re involved in those situations, it is vital to know your rights. Police often put much effort into ensuring they are correct before taking action, but there are times when their actions or assumptions are erroneous. In those instances, you may want to seek legal help from a professional attorney.

When do cops have to use reasonable suspicion or probable cause?

When cops stop someone asking some questions, they could need reasonable suspicion. To officially arrest a private or search a person’s property or possessions, they would need probable cause. Cops cannot search your property or belongings without a search warrant.

It is why probable cause is so important. The administrative agencies need the facts and evidence obtained by the cops to obtain a search warrant.

How do cops establish evidence for search warrants?

To obtain a search warrant, cops must apply for an inquiry warrant with a district or circuit court judge. Within the appliance, cops must use facts and circumstances that would lead a cheap person to believe that a crime has happened. Additionally, to the facts and circumstances, cops must include:

  • There must be enough evidence to initiate a search.
  • The site that the police officer wants to search.
  • The property or belongings can get seized.


If you think you can get arrested, a search warrant gets initiated against you, or if you got charged with a criminal offense, ask an experienced criminal defense attorney as soon as possible. 

An experienced lawyer can facilitate your understanding of the law and its application to your case. A lawyer can simplify your challenge of unlawful arrests and searches by filing a motion to suppress (exclude) evidence. A lawyer might make a motion to set aside information or charges if the lawyer thinks a judge might find that there is less evidence (less than probable cause) to support the case.

During the hearing, the defendant can argue that evidence didn’t exist within the circumstances leading up to the arrest. The case will be dropped if the prosecution does not support the evidence.


Reasonable suspicion could also be a step before probable cause. A criminal offense might have occurred if the police are reasonably suspicious. Things escalate to evidence when it becomes evident that a criminal offense has presumably been committed.

Almost as central because the necessity for facts is the requirement that, in determining whether officers have evidence and reasonable suspicion, the courts consider the totality of circumstances. 

It is often significant because it is the opposite of how some courts did things a few years ago. That is, they could utilize a “divide-and-conquer” approach which meant subjecting each fact to a careful assessment, then frequently ruling that the officers lacked probable cause or reasonable suspicion because none of the individual facts were trustworthy enough to prove the offense.


Can charges be dropped at an evidentiary hearing?

If the officer does not have a description and arrests a person walking down the street, the officer won’t have had probable cause to make the arrest. By showing the shortage of probable cause the court may drop or dismiss the fees.

What will happen if a police officer fails to establish reasonable suspicion or probable cause before making an arrest or a search?

The arrest and the search are considered unlawful. Any evidence collected before the arrest may not stand in court( the judge may not consider it) in the event of a trial, which can dramatically reduce the odds, that a criminal offense will be committed.

How much detail do police officers need to convince a judge to issue an arrest warrant or to justify a warrantless arrest?

In general, evidence requires quite a mere suspicion that a suspect committed a crime, but not the utmost amount of information as needed to prove the suspect guilty beyond a reasonable doubt.

Will reasonable suspicion alone cause an arrest?

If cops arrest you based on reasonable suspicion, you can be acquitted of any charges that the cops raise against you. Cops can only detain you if there’s evidence to do so and if there is sufficient evidence to convict you.