In Tennessee, many drug charges begin with a routine traffic stop. But if that stop or the search that follows violates your constitutional rights, the prosecution’s entire case could fall apart.
Both the U.S. Constitution and Tennessee law place strict limits on when and how police can stop a vehicle, detain someone, or search for evidence. If an officer fails to follow those rules, any drugs or other evidence found during the stop may not be allowed in court.
For that reason, one of the first things criminal defense attorneys look at is whether the stop and search were lawful. If not, it may be possible to get the evidence suppressed—and in some cases, this can lead to the dismissal of the charges.
This blog explains how Tennessee courts evaluate traffic stops and vehicle searches, the legal standards officers must follow, and how violations of those standards can impact a drug case.
What Is the “Fruit of the Poisonous Tree” Doctrine?
As mentioned above, when a traffic stop or search violates your constitutional rights, any evidence that results from that illegal conduct may be excluded from court. This concept is governed by a legal doctrine known as the “fruit of the poisonous tree.”
The doctrine is based on a simple idea: if the source of the evidence—the “tree”—is tainted by illegality, then anything gained from it—the “fruit”—is also tainted and generally cannot be used at trial. In the context of drug cases, this often means that drugs found in a vehicle, or statements made by a driver or passenger, may be suppressed if the traffic stop or search was unlawful.
This rule is rooted in the Fourth Amendment and enforced through the exclusionary rule, which bars the use of evidence obtained in violation of a person’s constitutional rights. Tennessee courts have long recognized and applied this principle to hold law enforcement accountable and to deter unlawful conduct.
In practical terms, the fruit of the poisonous tree doctrine can be a powerful defense tool. If key evidence—such as narcotics or paraphernalia—was discovered as a result of an illegal stop or search, it may be excluded from trial. Without that evidence, the State may have no choice but to dismiss the charges.
The Legal Standard for Traffic Stops in Tennessee
To determine whether evidence should be suppressed under the fruit of the poisonous tree doctrine, courts first look at the legality of the traffic stop itself. In Tennessee, the law is clear: a police officer must have a specific, objective reason to initiate a traffic stop. A stop may be lawful if an officer observes a traffic violation—like speeding, failing to signal, or a broken taillight. But the officer’s justification must be more than a hunch or vague suspicion.
The Tennessee Court of Criminal Appeals, in cases such as State v. Rowland, has reinforced that the legality of a stop is judged by an objective standard. That means the court examines whether a reasonable officer in the same circumstances would have believed that a traffic violation or criminal act had occurred—not simply whether the officer personally believed it. If the stop lacks that objective foundation, any evidence discovered afterward can be challenged as unlawfully obtained and possibly excluded from trial.
Common Reasons to Challenge Traffic Stops in Court
Even when a traffic stop appears routine, there are several ways it may violate constitutional protections. As part of building a strong defense, our criminal defense attorneys closely examine the officer’s justification for the stop and how the encounter unfolded. If the officer deviated from legal standards at any point, the resulting evidence may be subject to suppression.
Here are some of the most common issues that arise in Tennessee traffic stops:
Unsupported or Inconsistent Justifications
An officer’s stated reason for the stop must be supported by observable facts. If they claim the driver failed to maintain their lane or committed another violation, dash cam or body cam footage must back that up. When the footage contradicts the report—or shows no violation occurred—the stop may be ruled unlawful.
Vague or Subjective Observations
Courts routinely reject stops based on broad, subjective terms like “suspicious behavior” or “nervousness.” These impressions are not enough to establish reasonable suspicion. The law requires specific and articulable facts, not vague instincts or generalizations.
Prolonged Detention Without Cause
Once the initial reason for the stop is resolved, the officer cannot prolong the encounter without additional legal justification. For instance:
- Detaining a driver longer to ask unrelated questions or wait for a K-9 unit without new suspicion is a constitutional violation.
- Expanding the stop into a drug investigation without probable cause can trigger a suppression motion.
Misuse of “Plain View” or “Plain Smell”
Police frequently justify vehicle searches by claiming they saw drugs in “plain view” or smelled the odor of marijuana. However, courts require that it be immediately apparent that what the officer observed is illegal. If the officer had to manipulate items to see them, or if what was visible was ambiguous (such as a legal container), the plain view exception may not apply.
Similarly, relying solely on the odor of marijuana has become a far weaker justification—especially after the 2024 decision in State v. Green. That case recognized the difficulty in distinguishing between illegal marijuana and legal hemp products, which often look and smell the same. As a result, Tennessee courts now require a search based on smell to be supported by additional evidence, not just the officer’s claim of odor.
What Happens When Evidence Is Suppressed?
When a court determines that a traffic stop or search violated the Fourth Amendment, the evidence obtained as a result—such as illegal drugs, paraphernalia, or incriminating statements—may be suppressed, meaning it cannot be used by the prosecution at trial.
The impact of evidence suppression can be significant:
- If the suppressed evidence is the primary basis of the charges—as is often the case in drug possession or distribution cases—the State may be unable to proceed with prosecution.
- In many instances, suppression leads directly to a dismissal of the charges.
- Even if the case is not dismissed outright, suppression can weaken the prosecution’s leverage, leading to reduced charges or more favorable plea agreements.
The process begins with a motion to suppress, which is a formal request asking the court to exclude certain evidence. These motions require a thorough legal and factual analysis—often involving review of dash cam footage, officer body cam recordings, and patrol car logs—to identify exactly where the stop or search went wrong.
Because suppression can dramatically shift the balance of power in a case, it is one of the most powerful tools available to a defense attorney—especially in drug-related prosecutions where the evidence is often the result of a vehicle search.
How A Drug Defense Attorney Can Help
Successfully challenging a traffic stop or search isn’t just about knowing the law—it requires the ability to apply the law strategically and with precision. These cases often hinge on small details: a word in a police report, a few seconds of dash cam footage, or whether an officer asked the right question at the right time.
At Barnes & Fersten, we focus on exactly these kinds of issues, thoroughly analyzing the evidence to build a strong defense for your case. Our attorneys know how to:
- Pinpoint constitutional violations in vehicle stops and searches
- Analyze dash cam and body cam footage for inconsistencies
- Stay up to date and apply evolving Tennessee case law to protect our clients
- Craft and argue effective motions to suppress that can end a case before it goes to trial
We’ve helped clients across East Tennessee get serious charges dismissed by challenging how the evidence was obtained. And in many drug cases, that’s the key issue. If the search was illegal, the case often falls apart.
In a legal system that moves quickly, and where the consequences can last a lifetime, you need a criminal defense attorney who knows what to look for—and how to fight back when your rights are violated.
Don’t Let an Illegal Traffic Stop Cost You Everything
From the moment you’re pulled over, every detail matters: why the stop occurred, how the officer conducted the search, and whether the justification meets the standards set by Tennessee law. When police get it wrong, an experienced defense attorney can hold them accountable—and that can be the difference between a conviction and a clean slate.
Our drug defense attorneys fight to uncover constitutional violations and challenge unlawful searches head-on. If you’ve been charged with a drug offense following a traffic stop, don’t automatically assume you’re guilty. Let our legal team review your case and help protect your future.
Call us today at 865-805-5703 for a free consultation, or contact us online to discuss your case and explore your legal options.
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, Roane County, Anderson County, and Cumberland County.
