Police officers need legal justification before they can stop, search, or arrest someone. This legal justification falls under two of the most important legal standards in criminal cases: probable cause and reasonable suspicion. These standards affect everything from traffic stops and searches to the evidence prosecutors may try to use against you in court.
When you know the difference between probable cause and reasonable suspicion, you can better recognize when law enforcement may have broken their own rules. If they did, some or all of the resulting evidence can be excluded from a criminal case, affecting the prosecution’s ability to proceed. An experienced defense attorney at the Law Offices of Jonathan F. Marshall can work to exploit such an error and break the case against you.
What Is Probable Cause?
Probable cause is a higher legal standard than reasonable suspicion. Police generally need probable cause before infringing on anyone’s rights. That includes making an arrest or searching someone’s person or property, with or without a search warrant.
When officers have enough facts or evidence to reasonably believe that a crime occurred, probable cause exists. Courts do not require absolute proof before an arrest on probable cause. Officers only need enough reliable information to support a reasonable belief that a crime was committed and a specific person or place was involved. Police may also obtain a search or an arrest warrant from a judge after presenting evidence that supports criminal probable cause.
For example:
- An officer sees illegal drugs in plain view during a traffic stop.
- A store employee identifies a suspected shoplifter using surveillance footage.
- A driver fails a field sobriety test and shows signs of intoxication.
- Witness statements connect someone to a recent burglary.
- Police discover stolen property inside a vehicle during a lawful search.
Probable cause often comes from a combination of evidence, including:
- Personal observations
- Witness statements
- Physical evidence
- Information from informants
Without probable cause, an arrest or search may violate your Constitutional rights.
What Is Reasonable Suspicion?
Reasonable suspicion is a lower legal standard than probable cause. Police may briefly stop and investigate someone if they can point to specific facts suggesting criminal activity may be occurring.
An officer can’t just rely on a vague feeling or personal assumption to stop and investigate. Reasonable suspicion requires observable facts and rational conclusions based on those facts. This standard commonly applies during:
- Traffic stops
- Investigatory detentions
- Pat-down searches for weapons
- Pedestrian stops
Here are some common examples of reasonable suspicion:
- A driver repeatedly swerves across traffic lanes late at night.
- Someone runs away immediately after nearby reports of gunfire.
- A person repeatedly tries car door handles in a parking lot.
- A suspect matches the description from a recent robbery report.
- An officer smells alcohol coming from a vehicle.
Courts also generally allow officers to conduct a limited pat-down search during a stop if they reasonably believe someone may be armed and dangerous. This type of search is meant to protect officer safety, not gather evidence, although in practice it can do both.
These situations may justify a temporary stop or investigation, but they may not automatically justify an arrest. The length and scope of the stop are also limited. Police cannot prolong a detention without additional evidence that supports probable cause or continued reasonable suspicion. When law enforcement officers detain you past that point, it becomes a de facto arrest – an actual but unofficial arrest.
Main Differences Between Probable Cause and Reasonable Suspicion
The main difference between reasonable suspicion and probable cause involves the amount of evidence police need before taking action. Reasonable suspicion allows officers to briefly stop and investigate someone, while probable cause permits arrests and broader searches.
For example:
- The evidence required – Reasonable suspicion requires specific facts suggesting criminal activity may have happened or is in progress. Probable cause requires stronger evidence that would lead a reasonable person to believe a crime occurred.
- What the police can do – Reasonable suspicion may legally justify a temporary traffic stop, brief detention, or limited weapons frisk. Probable cause may justify an arrest or a search, including issuing a search warrant and seizing evidence connected to a crime.
- How long the encounter can last – Stops based on reasonable suspicion must be temporary and limited in scope. Probable cause allows police to take someone into custody.
Despite all these differences, both standards stem from Fourth Amendment protections against unreasonable searches and seizures. Courts are supposed to closely review arrests and searches because they involve greater intrusions on personal liberty.
How a Criminal Defense Lawyer Can Use These Standards in Your Defense
If police violated your Constitutional rights during a stop, search, or arrest, your lawyer may challenge whether any resulting evidence can be used against you. When courts exclude key evidence, prosecutors may lose an important part of their case. In some cases, that can lead to reduced charges – or even an acquittal or dismissal.
Depending on your case, your lawyer may challenge the:
- Initial stop – Police must identify specific facts supporting their reasonable suspicion before stopping someone. If an officer relied only on a hunch, that could be illegal.
- Search – Your lawyer may question whether officers exceeded the scope of a lawful search, whether your consent was voluntary, whether their warrant was valid, or whether police improperly relied on an exception to the warrant requirement.
- Arrest – Your lawyer may argue that the police lacked enough evidence connecting you to criminal activity at the time of the arrest. If the court agrees, any illegally obtained evidence could be inadmissible.
Small details can become very important when courts review search and seizure issues, so it’s important to have an experienced attorney on your side.
Call Our New Jersey Criminal Defense Lawyers
If you were arrested after a traffic stop, search, or police investigation, the attorneys at the Law Offices of Jonathan F. Marshall can help you understand whether law enforcement had legal grounds for their actions.
Our team has more than 250 years of combined experience defending against criminal charges throughout New Jersey.* With 20 lawyers and 18 office locations across the state, we provide quality representation backed by extensive courtroom experience – and our clients agree. As our client, Tyler, said:
“Cops can be very unfair so you better call Jonathan if you are on the short end of the stick. I hired him because I was stopped and arrested for a bogus reason and then issued 10 tickets and a criminal offense for possession of cds. The car never should have been stopped or ever searched. There was no valid basis but the police officer was just going to nail me no matter what. Jonathan made sure that I got a fair shake in court. He fought for me and did a great job. I still don’t have a record and kept my license. He is a great attorney for you to hire. I highly suggest that you give him a call.”
Contact us today to find out how we can help.
*Each case is unique, and past results do not guarantee future outcomes.
