Rick Cofer

Rick Cofer is a partner at Cofer & Connelly, an Austin- based firm representing Texans statewide in serious felony and drug cases. He has practiced law for 15 years and tried more than 100 cases to a judge or jury.

What’s in a name? That which we call weed/by any other name would smell as sweet

We all dread that one infamous line in an offense report: “I detected what I know through my training and experience to be the odor of marijuana.” This one sentence has stymied innumerable motions to suppress. Prior to 2018, Texas courts consistently held that the odor of marijuana alone provided reasonable suspicion to conduct an investigative detention and provided probable cause for a warrantless search of a vehicle or its occupants during a traffic stop.

Two recent pieces of legislation have radically altered the cannabis regulatory framework. For criminal defense practitioners, understanding these regulatory changes is critical to advancing the novel legal challenges to push back on “odor of marijuana” traffic stops and detentions.

Regulatory Changes

The federal “Farm Bill,” signed in 2018, and the Texas “Hemp Bill,” signed in 2019, both altered the definition of cannabis, a type of flowering plant in the Cannabaceae family. Prior to the passage of the Farm Bill, all cannabis plants were generally considered illegal substances under the federal Controlled Substances Act. The Hemp Bill amended the definition of “marihuana” in the Texas Health and Safety Code to exclude “hemp.” Hemp is defined as cannabis with a THC concentration at or below .3%. The possession of any usable quantity of marijuana—now defined as cannabis with a THC concentration higher than .3%‑‑remains a criminal offense.1 Possession of hemp is not.

What might at first glance read like a trivial definitional change has significant ramifications for criminal defense attorneys and our clients. “Hemp” and “marijuana” are functionally made‑up labels for different uses of the same plant. They are differentiated legally only by THC concentration. Determining the THC concentration of either substance requires lab testing. It is impossible to distinguish hemp from marijuana by human sight or by odor alone. More on this below, but dogs can’t smell the difference either.

As a result of the reforms to cannabis law, criminal defendants nationwide have begun challenging the “odor of marijuana” as a standalone basis for a reasonable suspicion or probable cause finding. Following passage of the Farm Bill and Hemp Bill, Texas courts have yet to clarify whether the “odor of marijuana” alone still provides reasonable suspicion or probable cause.

This is just beginning in Texas

The issue has been raised recently in at least one Texas court of appeals. In McAfee-Jackson v. State, the officer conducted a vehicle search after smelling the odor of marijuana coming from the vehicle during a traffic stop. A small amount of marijuana was located during the search. The appellant filed a motion to suppress, arguing that odor of marijuana alone did not provide probable cause for the search because the officer could have smelled legal hemp. At the suppression hearing, the trooper testified that he had probable cause to search the vehicle due to the odor of marijuana, but he conceded that he could not distinguish marijuana from hemp by either appearance or smell. The appellant was found guilty of possession of marijuana. On appeal, the appellant challenged the trial court’s denial of her motion to suppress. Unfortunately, the court declined to rule on the substantive issue because it was not properly preserved.

It will likely not be long before a Texas court of appeals is again confronted with the question of whether the odor of marijuana alone still provides reasonable suspicion or probable cause.

Looking for guidance outside Texas

Courts in other jurisdictions with more liberal cannabis laws provide a useful point of comparison. In states that have legalized cannabis, courts are consistently holding that the odor of marijuana alone cannot justify a detention or search.

The Superior Court of Pennsylvania held that the odor of marijuana does not “always” establish probable cause for a search but rather may be “a factor” when assessing probable cause in a totality‑of‑the‑ circumstances test. In Commonwealth v. Grooms, an officer conducted a vehicle search based solely on the odor of fresh marijuana coming from the vehicle. Two months prior to the search, Pennsylvania legalized dry‑ leaf marijuana for medical purposes. The driver of the vehicle filed a suppression motion, which the trial court denied. On appeal, the appellant argued that the mere odor of marijuana is not alone suggestive of criminal activity in Pennsylvania. The Court agreed: “[T]he odor of marijuana alone, absent any other circumstances, cannot provide individualized suspicion of criminal activity,” due to the fact that “the police cannot discern lawful from unlawful conduct by the odor of marijuana alone.”

The Court of Special Appeals of Maryland recently addressed the question of whether the odor of marijuana alone may justify an investigative detention, or Terry stop. In In re D.D., police conducted a “stop and frisk” of a juvenile after an officer claimed he smelled the odor of marijuana coming from the juvenile. Defense counsel filed a motion to suppress the initial detention.

The trial court denied the motion. On appeal, the juvenile argued that the odor of marijuana alone is not an indicator of criminal activity. Important in the court’s analysis was the fact that in 2014 the Maryland legislature had decriminalized possession of less than 10 grams of marijuana. In the court’s reasoning, because possession of less than 10 grams of marijuana was no longer a crime, and odor alone cannot indicate the quantity of marijuana in someone’s possession, the odor of marijuana “cannot, by itself, provide reasonable suspicion that the person is in possession if a criminal amount of marijuana or otherwise involved in criminal activity.”

Other courts in states that have decriminalized small quantities of marijuana have held that the odor of marijuana alone no longer provides reasonable suspicion of criminal activity. The Supreme Court of New Hampshire concluded that following the passage of a marijuana decriminalization statute, the odor of marijuana alone does not, per se, support a reasonable, articulable suspicion of criminal activity. However, the Court left open the possibility that the odor of marijuana “remains a relevant factor” in a reasonable suspicion analysis, if additional factors of potential criminality are present.

Similarly, the Supreme Judicial Court of Massachusetts held that following the passage of a marijuana decriminalization statute, the odor of marijuana alone does not provide reasonable suspicion of criminal activity.

Don’t forget the dogs

Legal reforms of marijuana law also have implications for probable cause searches supported by dog sniff “alerts.” The Fifth Circuit previously held that a dog alerting to the presence of narcotics inside a vehicle establishes probable cause to search the vehicle. As explained by the Supreme Court, open‑air dog sniffs that could only reveal the presence of contraband are not “searches” and do not implicate the Fourth Amendment.

Dogs that are trained to alert to marijuana could alert to a substance that is legal to possess. Dogs cannot distinguish between marijuana and hemp when making an alert, and a dog will alert the same if it has detected marijuana, methamphetamine, cocaine, or any substance it is trained to detect. In Texas, the Austin Police Department have reportedly directed officers to use a positive alert as only one piece in establishing probable cause for a search. Following the passage of the Hemp Bill, no Texas appellate court has directly addressed the question of whether a positive alert from a canine that is trained to detect the presence of marijuana—which could be easily confused by the canine for legal hemp—still establishes probable cause for a search. However, if a narcotics dog could alert to a perfectly legal substance, such as hemp, it cannot be assumed that the dog could only alert to contraband. Therefore, the dog’s “sniff ” is now a search implicating Fourth Amendment rights, and the “alert” would not, on its own, provide probable cause of criminal activity.


Many Texas counties continue to prosecute the possession of even small amounts of marijuana, despite the practical reality that state laboratories still appear to have challenges with determining the concentration of THC in a substance. Local law enforcement in many counties will use the odor of marijuana as the sole basis for conducting a probable cause search of a vehicle. Despite changes in the law which legalize the possession of low‑ level THC cannabis (hemp), no Texas court to date has addressed the issue of whether the odor of marijuana alone still provides reasonable suspicion or probable cause, or whether a positive canine “alert” to cannabis provides probable cause to search. If Texas follows the reasoning of other state courts in similar predicaments, Texas is likely to modify its bright‑line rule regarding the odor of marijuana and probable cause. The odor of marijuana—which is indistinguishable from that of legal hemp—cannot alone provide reasonable suspicion of criminal activity since the police cannot distinguish lawful from unlawful conduct based on odor alone. When it comes to the human (or canine) nose, cannabis is cannabis, regardless of its THC concentration.


  1. Taylor State, 20 S.W.3d 51, 55-56 (Tex. App.— Texarkana 2000, pet. ref’d).
  2. Razo State, 577 S.W.2d 709, 711 (Tex. Crim. App. [Panel Op.] 1979).
  3. Jordan State, 394 S.W.3d 58, 64-65 (Tex. App.—Houston [1st Dist.] 2012, pet. ref’d).
  4. Agriculture Improvement Act of 2018, L. No. 115‑ 661, § 10113 (codified at 7 U.S.C. §§ 1639o—1639s).
  5. H. B. 1325,86th Leg., (Tex. 2019), https://capitol.texas.gov/tlodocs/86R/billtext/pdf/HB01325F.pdf#navpanes=0.
  6. Rupasinghe, H., Davis, A., Kumar, S. K., Murray, B., & Zheljazkov, V. D. (2020).“Industrial Hemp (Cannabissativa subsp. sativa) as an Emerging Source for Value‑Added Functional Food Ingredients and Nutraceuticals.” Molecules (Basel, Switzerland), 25(18), 4078. https://doi.org/10.3390/molecules25184078.
  7. Molitor v. City of Scranton, CV 3:20‑1266, 2021 WL 3884463, at *5 (M.D. Pa. Aug. 31, 2021).
  8. Tex. Health & Safety Code Ann. § 481.002(26).
  9. Tex. Agric. Code § 121.001.
  10. Tex. Health & Safety Code § 481.121(a).
  11. Evaluating the Impact of Hemp Food Consumption on Workplace Drug Tests, (“The primary difference is that marijuana has a higher concentration of the psychoactive compound cannabinoid delta 9tetrahydrocannabinol, more commonly known as THC”).
  12. McAfee-Jackson State, No. 09‑19‑00430‑CR, 2021 Tex. App. LEXIS 7297, at *1 (Tex. App.—Beaumont Sep. 1, 2021, no pet.).
  13. Commonwealth v. Grooms, 247 A.3d 31, 41 (Pa. Super. Ct. 2021).
  14. In re D.D., 250 A.3d 284, 286 (Md. Ct. Spec. App. 2021) cert. granted, 257 A.3d 1162 (2021).
  15. State v. Francisco Perez , 239 A.3d 975, 985 (2020).
  16. United States v. Sanchez-Pena, 336 F.3d 431, 444 (5th Cir. 2003).
  17. Illinois v. Caballes, 543 U.S. 405, 408 (2005).
  18. Mark Wilson, Law and Odor: Police Hazy on How to Use Drug-Sniffing Dogs Under Texas Hemp Law, STATESMAN (Jul. 12, 2019), https://www.statesman.com/news/20190712/law‑and‑odor‑police‑hazy‑on‑how‑to‑use‑drug‑sniffing‑dogs‑under‑texas‑hemplaw [https://perma.cc/9C8J‑GWNX].
  19. Law, STATESMAN (Jul. 12, 2019), https://www.statesman.com/news/20190712/law‑and‑odor‑police‑hazy‑on‑how‑to‑use‑drug‑sniffing‑dogs‑under‑texas‑hemplaw [https://perma.cc/9C8J‑GWNX].
  20. Michael Barajas, Texas (Kinda, Sorta) Accidentally Decriminalized Weed. Now What?, TEX. OBSERVER (Aug. 20, 2019), https://www.texasobserver.org/texas‑kinda‑sortaaccidentally‑decriminalized‑weed‑now‑what/ [https://perma.cc/WE9G‑JTE3].