The Fourth Amendment to the U.S. Constitution is clear: people have the right to be secure in their persons, houses, papers, and effects against unreasonable searches and seizures. In Texas, law enforcement officers must have a valid warrant, or one of a few narrowly defined exceptions, before they can search your vehicle, home, or person. When they don’t, evidence obtained can (and often should) be thrown out entirely under the “fruit of the poisonous tree” doctrine.
At Thornton Criminal Defense, we don’t just defend against charges; we aggressively protect your constitutional rights. Board-Certified Criminal Defense Attorney Brad Thornton, a former Chief Prosecutor in South Texas, knows exactly how police and prosecutors try to justify warrantless searches, and how to dismantle those justifications in court. If an officer lacked lawful authority to initiate a stop or conduct a search, the evidence they discover (drugs, weapons, cash, or anything else) may be inadmissible. That single legal victory can collapse the State’s entire case.
The Fruit of the Poisonous Tree: How One Illegal Step Taints Everything
The “fruit of the poisonous tree” doctrine, established by the U.S. Supreme Court in Wong Sun v. United States (1963) and reinforced in countless Texas cases, holds that evidence obtained as a direct result of an unconstitutional search or seizure is inadmissible. The metaphor is straightforward: if the tree (the illegal search) is poisonous, so is its fruit (the evidence found). Common Texas examples:
- An officer pulls you over without reasonable suspicion (no traffic violation, no matching description of a suspect vehicle). During the stop, they spot a baggie of marijuana under the seat in plain view.
- Police enter your home without a warrant and without exigent circumstances, then find drugs or firearms.
- An unlawful pat-down during a consensual encounter yields a concealed weapon.
In each scenario, if the initial intrusion violated the Fourth Amendment, the discovered evidence is “fruit” and must be suppressed, often ending the prosecution’s case.
Key Exceptions Prosecutors Rely On and How We Challenge Them
Texas courts and the U.S. Supreme Court recognize a handful of warrantless search exceptions. Prosecutors will argue one of these applies; our job is to prove it doesn’t.
- Plain view doctrine: Officers may seize evidence in plain view only if they are lawfully in the position to see it. If the initial stop or entry was illegal, plain view doesn’t save the evidence. We scrutinize dash-cam footage, body-cam video, and officer reports to show the view was obtained unlawfully.
- Consent: Consent must be voluntary, and not coerced by a show of authority. We examine the totality of circumstances: Were multiple officers present? Was the person told they could refuse? Was English their first language? Consent obtained under duress is invalid.
- Exigent circumstances: Police may enter without a warrant if there’s an immediate threat to life, risk of evidence destruction, or hot pursuit. These claims are frequently exaggerated. We demand proof of true exigency, often revealing officers created the emergency themselves.
- Search incident to arrest: Limited to the arrestee’s immediate grabbing area. In vehicles, it applies only if the arrestee is unsecured and within reaching distance (Arizona v. Gant, 2009). We challenge overbroad “vehicle searches incident to arrest” that reach the trunk or glove box without justification.
- Automobile exception: Vehicles receive a lower expectation of privacy, allowing warrantless searches with probable cause. However, the initial stop still requires reasonable suspicion. No lawful traffic stop means no automobile exception.
Building a Winning Motion to Suppress in San Antonio and Bexar County
A motion to suppress is the most powerful tool in fighting unlawful search and seizure. When granted, it excludes tainted evidence, frequently leading to dismissal or acquittal. At Thornton Criminal Defense, we file these motions aggressively and prepare them for evidentiary hearings where officers testify under oath. Here are some key steps we take:
- Review body-cam, dash-cam, and audio evidence for inconsistencies.
- Subpoena dispatch logs, CAD reports, and officer notes.
- Cross-examine officers on training, departmental policies, and prior testimony.
- Present expert testimony when needed (on field sobriety or drug-dog reliability).
- Argue Texas-specific precedents from the Court of Criminal Appeals and San Antonio appellate courts.
Brad Thornton’s experience as a former prosecutor who trained officers and presented cases to grand juries gives us unique insight into how Bexar County prosecutors defend these searches and where their arguments are weakest.
Protecting Your Rights in Drug, Weapons, and Other Cases
Unlawful search and seizure defenses are especially critical in:
- Drug possession cases: Where the State’s evidence often comes from a vehicle or pat-down search.
- Weapons charges: Many concealed-carry or unlawful-possession cases hinge on the legality of the initial encounter.
- DWI stops: Improper traffic stops can suppress breath/blood results and field sobriety observations.
When we win a suppression motion, the State often has no choice but to dismiss or reduce charges dramatically.
Why Choose a Specialist to Fight for Your Fourth Amendment Rights
Board-Certified in Criminal Law and with over a decade of courtroom experience (including more than 100 jury trials), Brad Thornton combines constitutional expertise with practical knowledge of South Texas courts. We treat every client as an individual deserving of full constitutional protection, not just another case number.
If you’ve been charged after what felt like an improper stop, search, or seizure, don’t assume the evidence is admissible. Let us evaluate whether the State violated your Fourth Amendment rights and fight to exclude the tainted evidence.
Contact a drug possession defense lawyer at Thornton Criminal Defense today for a free, confidential consultation. We’re ready to protect your constitutional rights and fight for the best possible outcome in your case.
William Gall is a seasoned attorney specializing in civil litigation and family law. With a legal career spanning over two decades, William has built a reputation for his meticulous attention to detail and his unwavering commitment to justice. In addition to practicing law, he is a prolific writer, contributing regularly to various legal blogs where he shares his insights on current legal trends, case law, and best practices. His articles are well-regarded in the legal community for their thorough research and practical advice, making complex legal concepts accessible to both legal professionals and the general public.