If you’ve ever been pulled over by police in Tennessee, you might have wondered: “did they have the right to stop me in the first place?” In criminal defense cases, one of the most important questions our attorneys ask is whether law enforcement had reasonable suspicion to justify the stop.
This legal concept plays a critical role in cases involving DUI charges, drug possession, firearm offenses, and other criminal investigations. It’s often the first point where your constitutional rights come into play, and if the officer didn’t have a lawful reason to detain or search you, any evidence they collected could be thrown out.
In this blog, we’ll break down what “reasonable suspicion” really means under Tennessee law, how it differs from probable cause, and why it’s so often the focus of courtroom challenges.
What Is Reasonable Suspicion?
Under Tennessee law, reasonable suspicion is a legal standard that allows a police officer to briefly detain someone if they can point to specific facts suggesting that person is involved in criminal activity. It’s not enough for an officer to have a hunch or a vague feeling—there must be clear, articulable reasons behind the stop.
This concept comes from the landmark U.S. Supreme Court case Terry v. Ohio (1968), which held that officers can stop and frisk someone if they have reasonable suspicion that a crime is occurring or about to occur. Tennessee courts have adopted this standard and apply it in situations like traffic stops and pedestrian encounters.
Reasonable suspicion is what gives law enforcement the legal authority to:
- Pull a driver over for suspected DUI or traffic violations.
- Temporarily detain a person on the street for questioning.
- Conduct a limited pat-down if they believe someone may be armed.
A key point is that reasonable suspicion requires specific, observable facts—such as a driver swerving across lanes, someone loitering in front of closed businesses late at night, or a person matching a description from a recent crime.
Common Situations Where Reasonable Suspicion Arises
1. Traffic Stops
A majority of DUI and drug cases begin with a traffic stop. To legally pull someone over, officers must observe a traffic violation or suspicious behavior. Common reasons cited include:
- Weaving within or between lanes
- Driving above or significantly below the speed limit
- Expired tags or a broken taillight
- Failure to use a turn signal
Even a minor infraction can lead to a stop, but what follows depends on whether the officer can build reasonable suspicion of criminal activity beyond the traffic offense.
2. Suspected DUI Investigations
After a stop, officers often look for signs of driving under the influence. Reasonable suspicion to investigate further may come from:
- The smell of alcohol or marijuana
- Slurred speech or bloodshot eyes
- Difficulty answering basic questions
- Open containers in plain view
These observations can lead to field sobriety tests or a breathalyzer, both of which must be supported by more than just a traffic violation.
3. Pedestrian Stops (Stop-and-Frisk)
In some cases, police stop individuals on foot if they believe criminal activity is happening or about to happen. Officers may claim reasonable suspicion based on:
- Nervous behavior or avoiding eye contact
- Loitering in high-crime areas
- Matching the description of a suspect
- Protrusions in clothes suggesting a concealed weapon
These stops can escalate quickly, and if police conduct a pat-down or search without justification, any evidence they find could be challenged.
4. Drug Possession or Firearm Investigations
In Knoxville and across East Tennessee, many drug and gun charges begin with stops based on vague behavior. For example:
- Sitting in a parked car in a known drug area
- Brief meetings or exchanges observed by police
- Furtive movements when officers approach
- Strong odors coming from a vehicle
Without concrete facts to support suspicion of a crime, these stops may be unconstitutional—something a skilled criminal defense attorney can argue in court.
What’s the Difference Between Reasonable Suspicion and Probable Cause?
Reasonable Suspicion: The Standard for Stops
Reasonable suspicion is the lower standard. It gives police the authority to briefly stop or detain someone if they observe facts that suggest a person might be involved in criminal activity. For example:
- An officer sees a car swerving between lanes at 2 a.m.
- Someone appears to be casing a business after hours.
- A vehicle fails to stop at a stop sign and accelerates rapidly after a patrol car approaches.
In each of these situations, the officer doesn’t yet have proof of a crime, but may have enough to investigate further.
Probable Cause: The Standard for Searches and Arrests
Probable cause is a higher legal threshold. It’s required before police can make an arrest or conduct a full search of your vehicle, home, or person. Officers must have facts and evidence that would lead a reasonable person to believe that a crime has been or is being committed.
Examples include:
- A failed field sobriety test and odor of alcohol supporting a DUI arrest
- A bag of marijuana visible in the center console
- A firearm found during a lawful frisk
Why This Matters in Criminal Defense
If the police escalated a stop into a search or arrest without having probable cause, this could potentially lead to reduced charges or even a dismissal. Our criminal defense attorneys routinely challenge arrests and searches that started with shaky claims of reasonable suspicion.
How Our Defense Attorneys Challenge Illegal Stops
In criminal cases across Tennessee, one of the most powerful defense tools is the ability to challenge an unlawful stop. If law enforcement did not have reasonable suspicion to pull you over, detain you, or search you, everything that followed may be thrown out in court. Our Knoxville criminal defense attorneys focus heavily on this issue, because if the stop wasn’t legal, the rest of the case may fall apart.
Challenging Illegal Stops With a Motion to Suppress
Our team regularly files motions to suppress evidence in cases involving illegal traffic stops or unconstitutional searches. A motion to suppress asks the judge to exclude any evidence that was obtained in violation of your Fourth Amendment rights, such as:
- Results of a breathalyzer or blood alcohol test
- Drugs, paraphernalia, or firearms found in a vehicle
- Statements made during an unlawful detention
- Field sobriety test results following a stop without reasonable suspicion
If the judge rules in your favor, prosecutors may have no choice but to reduce the charges or even dismiss the case entirely.
How We Investigate the Legality of a Stop
We take a proactive, evidence-based approach to every case. As your criminal defense lawyers, we thoroughly analyze whether police had specific, articulable facts to justify stopping or detaining you.
This includes:
- Reviewing dash cam and body cam footage
- Obtaining dispatch records, 911 calls, and officer notes
- Identifying discrepancies in the officer’s report or testimony
- Pinpointing when police escalated a stop without proper legal grounds
In many cases, we find that police relied on vague or subjective observations that don’t meet the legal standard for reasonable suspicion or probable cause.
What Happens If the Stop Was Illegal?
If the initial stop or detention violated your constitutional rights, the evidence gathered afterward is considered “fruit of the poisonous tree”, and it cannot be used against you in court. This could mean:
- A DUI charge may be dismissed if field sobriety tests were performed after an unlawful stop.
- Drug charges may be dropped if the search of your vehicle wasn’t properly justified.
- A firearm offense may be thrown out if police lacked probable cause to search.
Facing Criminal Charges? Get A Consultation Today
If you’ve been arrested or charged with a crime in Tennessee, the legality of the police stop that led to your case could be a critical defense issue. If officers lacked reasonable suspicion or probable cause, the evidence against you may be challenged or excluded. But these issues must be identified and raised early to be effective in court.
At Barnes and Fersten, we have a proven track record defending people facing criminal charges in Knoxville and throughout East Tennessee. We know how to evaluate police conduct, challenge illegal stops, and push back when your constitutional rights have been violated.
If you are facing criminal charges in East Tennessee, contact our law firm today by calling 865-805-5703 or filling out our contact form for a free consultation. We’ll review the facts of your situation, explain whether the stop was legal, and start building a defense focused on pursuing the absolute best outcome in your case.
Attorney At Law, Managing Partner
Brandon D. Fersten is an esteemed Knoxville attorney practicing DUI, criminal defense, and juvenile law. Known for his empathetic approach and commitment to his clients, he brings a record of favorable case outcomes including dismissals and not guilty verdicts at jury trials resulting in Brandon being recognized as one of the “Top 40 Under 40” in Criminal Defense, U.S. News’ Best Lawyers: “Ones to Watch,” and Super Lawyers’ “Rising Stars”. Brandon’s professional accolades, combined with his passion for justice, position him as a reliable criminal defense advocate in the East Tennessee legal landscape, including Knox County, Blount County, Sevier County, Loudon County, Roane County, Anderson County, Cumberland County, Hamblen County, Monroe County, and McMinn County.
