Southern Maine Criminal Lawyer Blog
John Scott Webb is a criminal defense lawyer in Saco and Portland, Maine. He explains the key differences between reasonable articulable suspicion (RAS) and probable cause (PC).
Reasonable Articulable Suspicion vs. Probable Cause in Maine
Reasonable Articulable Suspicion (RAS) allows a police officer to briefly stop and detain you. A Southern Maine police officer may stop you if you commit a traffic violation. Running a red light is one example.
The officer can also pull you over for what Maine law calls driving to endanger. Weaving between lanes is one example, and exceeding the speed limit by 30 miles per hour or more is itself a crime. The officer must articulate specific facts that led to their suspicion.
Common factors that establish RAS include traffic violations, erratic driving, or other suspicious behavior.
Probable Cause (PC) is a higher level of proof. It means facts and circumstances that would lead a reasonable person to believe a crime has been committed. PC is required before an officer can arrest you, apply for a search warrant, or conduct most searches.
PC is the higher standard. RAS allows for a brief investigative stop. PC is needed for more intrusive actions like arrests and vehicle searches.
An officer's observations during an RAS stop may escalate to PC. This escalation allows for an arrest. Factors that initially established RAS may develop into probable cause during an investigation.
OUI – Related Probable Cause and Articulable Suspicion
In a typical OUI (Operating Under the Influence) case in Maine, an officer needs RAS to pull over a vehicle. The officer might observe erratic driving. During the stop, if the officer develops PC that the driver is impaired, they can then make an arrest.
Observations that support PC include field sobriety tests and other signs of impairment.
Factors That Establish Reasonable Articulable Suspicion
In Maine, several specific behaviors can lead to reasonable articulable suspicion. These behaviors allow a police officer to initiate a traffic stop or brief investigative detention.
Traffic Violations: Any observed traffic or safety violation can provide RAS for a stop. This may include:
- Speeding
- Running a red light or stop sign
- Failing to use turn signals
- Driving with a broken taillight or headlight
Erratic Driving: Behaviors that suggest impaired driving can establish RAS, such as:
- Swerving across lanes
- Driving well under the speed limit without an apparent reason
- Straddling the center line or fog line (whether a single, brief straddle is enough depends on the circumstances)
Vehicle – Related Issues: Problems an officer can see with the vehicle itself, for example:
- Driving without visible license plates
- Operating a vehicle with significant visible damage
Suspicious Behavior: Observing anything odd about the driver's actions, including:
- A driver examining damage to their vehicle in a way that suggests a recent accident
- Behavior matching details from a credible tip, even if anonymous
Time and Location: While not sufficient alone, these factors can contribute to RAS when combined with other observations:
- Driving at unusual hours (such as leaving a bar at one a.m.) along with other suspicious behavior
- Being in an area known for criminal activity, coupled with other suspicious actions
- Matching the description of a suspect
- Furtive movements or attempts to flee
What Builds Probable Cause During an OUI Stop
Once the officer makes a lawful RAS stop, the investigation shifts. The officer must now gather evidence of probable cause. The following observations and tests commonly build PC for an OUI arrest:
- Odor of intoxicants – the smell of alcohol or marijuana on the driver's breath or inside the vehicle
- Bloodshot or glassy eyes – physical signs consistent with impairment
- Slurred speech – difficulty speaking clearly when responding to the officer's questions
- Admission of drinking – statements such as "I had a couple of beers" can weigh toward PC
- Field sobriety test performance – poor results on standardized tests such as the Horizontal Gaze Nystagmus (HGN), Walk-and-Turn, and One-Leg Stand
- Preliminary breath test (PBT) results – a roadside breath sample indicating the presence of alcohol
No single factor is required. Maine courts assess the totality of the circumstances. The officer's combined observations during the stop decide whether probable cause exists.
A driver who smells of alcohol, has glassy eyes, and performs poorly on field sobriety tests may give the officer PC to arrest. This holds true even if no single observation would be enough on its own.
RAS requires more than mere speculation or an unsubstantiated hunch. The officer must articulate specific facts that led to their suspicion. Also, while a single factor might not establish RAS, a combination of factors can often meet the threshold.
RAS is a lower standard than probable cause. It allows for a brief investigative stop. More evidence is typically needed to escalate to an arrest or search.
Articulable Suspicion Definition: What "Articulable" Means
The definition of articulable is simple. Articulable means capable of being clearly expressed in words. In legal terms, the meaning is straightforward. An officer must state specific, observable facts out loud. The officer cannot rely on a hunch or gut feeling.
The articulable definition centers on the ability to put reasons into words. Another person can then evaluate those reasons.
Articulable suspicion refers to a suspicion of criminal activity that an officer can explain. The officer points to concrete facts. Put the two words together to define articulable suspicion: a suspicion the officer can state in words. It is not enough for an officer to say "something felt wrong." The officer must describe what they saw, heard, or otherwise observed.
Reasonable articulable suspicion adds a layer of objectivity. The facts the officer articulates must be ones that a reasonable person would view as grounds for suspicion. This standard prevents stops based on personal bias or vague instinct.
Courts evaluate whether the articulated facts, taken together, would lead a reasonable officer to suspect criminal activity may be occurring. An officer's ability to identify specific facts justifies a brief investigative stop. These facts may include a traffic violation, erratic driving, or physical signs of impairment.
The Legal Standard for Reasonable Articulable Suspicion
The reasonable articulable suspicion standard comes from a landmark U.S. Supreme Court decision. In Terry v. Ohio, 392 U.S. 1 (1968), the Court addressed the Fourth Amendment standard for police stops.
The Court held that the Fourth Amendment permits a police officer to conduct a brief investigatory stop. The officer must point to specific and articulable facts. These facts, taken together with rational inferences, must reasonably warrant the stop.
An officer does not need probable cause to pull someone over or briefly detain them. Reasonable articulable suspicion is a lower threshold. The officer must have more than a bare hunch. But the officer needs less proof than what is required for an arrest.
Probable cause is the higher standard. Facts and circumstances must be sufficient to lead a prudent person to believe a crime has been or is being committed. Probable cause is needed for search warrants and most warrantless searches. Maine law also limits arrests without a warrant: for a Class D or Class E crime, which includes a first OUI, the crime must generally happen in the officer's presence.
The gap between the two standards is wide. Reasonable articulable suspicion justifies a brief, limited intrusion. Probable cause justifies far more intrusive government action.
Maine courts apply the same constitutional framework. The Maine Constitution protects against unreasonable searches and seizures. Maine courts analyze traffic stops under that provision as well as Fourth Amendment doctrine.
Whether a stop was lawful depends on the specific facts of each case. Courts look at the totality of circumstances the officer faced at the moment of the stop.
Side-by-Side: What Each Standard Lets an Officer Do
The distinction between reasonable articulable suspicion and probable cause determines what a police officer can and cannot do. Both are constitutional standards. They differ in the level of certainty required and the actions they authorize.
Reasonable Articulable Suspicion (RAS):
- Level of certainty: A reasonable belief, based on specific facts, that criminal activity may be afoot
- What it authorizes: A brief investigatory detention (a "Terry stop"), limited questioning, and a pat – down for weapons where the officer reasonably suspects the person is armed and dangerous
- Duration and scope: Must be brief and narrowly focused on confirming or dispelling the suspicion
Probable Cause (PC):
- Level of certainty: Facts and circumstances sufficient to lead a prudent person to believe a crime has been or is being committed
- What it authorizes: A full arrest, most warrantless searches, and application for search warrants
- Duration and scope: Allows extended detention, booking, and a full search incident to arrest
Example: A driver drifts across the fog line once at one-thirty a.m. That single observation may give an officer RAS to start a traffic stop. During the stop, the officer smells alcohol. The officer notices bloodshot eyes. The officer asks the driver to perform field sobriety tests.
The driver fails the walk – and – turn and one – leg stand tests. The driver admits to drinking. Those combined observations may rise to probable cause. The officer can then arrest the driver for OUI.
RAS opens the door to a brief stop. What the officer observes during that stop can build to probable cause. Or it may not.
A lawyer who works in Maine criminal defense can check whether each stage of the stop met the legal standard.
The Importance of Challenging RAS and PC
When a defendant argues that the officer lacked reasonable articulable suspicion, the defense files a motion to suppress evidence. When the defendant argues the officer lacked probable cause for the arrest, the defense also files a suppression motion.
A suppression motion invokes the exclusionary rule. This rule prevents the government from using evidence obtained through an unconstitutional seizure.
A successful suppression motion can remove key evidence from the state's case. In OUI cases, this evidence may include the officer's observations of impairment. It may include the driver's statements, field sobriety test results, and breath or blood test results. It may include any physical evidence found in a search of the car.
When suppressed evidence is central to the charges, the state may have no choice but to dismiss the case.
Several challenges come up often in Maine courts:
- Challenging whether a traffic violation happened – If dashcam or body camera footage shows the driver did not commit the violation the officer claims, the stop itself may be unlawful.
- Challenging whether driving behavior rose to RAS – A single, brief drift across a lane line may not meet the threshold. This depends on the circumstances.
- Challenging whether observations established PC before arrest – If the officer arrested the driver before doing field sobriety tests or gathering enough signs of impairment, the arrest may lack probable cause.
Whether a stop was lawful is always a fact – specific question. Courts look at the totality of what the officer knew at the moment of the stop or arrest. Even small details can decide whether the constitutional standard was met. These details include the time of night, road conditions, or how good the officer's notes were.
How RAS and PC Affect OUI Cases in Maine
In Operating Under the Influence (OUI) cases, the gap between RAS and PC matters a lot.
An officer needs RAS to start a traffic stop. The officer might observe a vehicle swerving. During the stop, the officer builds PC from what they see and from field sobriety tests. Only with PC can the officer make an arrest for OUI.
John Webb has successfully defended many clients. He showed that officers lacked proper RAS for the first stop. He also showed that officers failed to establish PC before an arrest.
Protecting Your Rights in Maine
The legality of the stop and the arrest can decide whether evidence against you can be used. A lawyer who digs into RAS and probable cause in your case can make a big difference.
If the officer lacked reasonable articulable suspicion for the initial stop, key evidence may be subject to suppression. If probable cause did not exist before your arrest, evidence may also be suppressed.
Webb Law Firm focuses on criminal defense and OUI defense across Southern Maine. John Webb knows how Maine courts judge the legality of traffic stops and arrests. He works to find constitutional violations that can change the course of a case.
If you have been charged with OUI or another crime in Maine, contact Webb Law Firm for a free consultation. A close look at the facts of your stop and arrest is the first step. This review protects your rights and your future.
Frequently Asked Questions
What Does "Articulable" Mean in a Legal Context?
Articulable means capable of being clearly stated in words. In law, it requires a police officer to describe specific, observable facts that justify their actions. The officer cannot rely on a vague feeling or hunch. The officer must explain exactly what they saw or heard that raised suspicion.
What Is the Definition of Reasonable Articulable Suspicion?
Reasonable articulable suspicion is the legal standard that allows a police officer to briefly stop and detain a person. The officer must point to specific facts that would lead a reasonable person to suspect criminal activity may be occurring. This standard comes from the U.S. Supreme Court's decision in Terry v. Ohio (1968).
What Is the Difference Between Reasonable Articulable Suspicion and Probable Cause?
Reasonable articulable suspicion is the lower standard. It allows an officer to conduct a brief investigatory stop. Probable cause is higher. It requires enough facts to lead a reasonable person to believe a crime has been committed. Probable cause is needed for arrests, search warrants, and most searches.
Can a Maine Police Officer Pull Me Over Without Reasonable Articulable Suspicion?
Generally, no. Under the Fourth Amendment and the Maine Constitution's search and seizure guarantee, a traffic stop is a seizure that requires reasonable articulable suspicion. If an officer stops you without RAS, any evidence gathered during that stop may be challenged and potentially suppressed in court.
What Happens if the Court Finds an Officer Lacked Reasonable Articulable Suspicion for My Stop?
If a court determines the officer did not have reasonable articulable suspicion, the stop was unconstitutional. The court may suppress all evidence obtained as a result of that stop. This includes the officer's observations, your statements, field sobriety test results, and breath or blood test results. In many cases, this leads to dismissal of the charges.