he value of drug detection dogs cannot be overstated, but no law enforcement agency should forget the importance and accuracy of the human sense of smell. And nowhere is that sense more valuable than in the investigation of narcotics.
Strong Smell of Marijuana
In June 2003 police officers in Richmond, Virginia, were patrolling a neighborhood known for drug trafficking. They noticed a group of people gathered on a street corner, including Deute Humphries. One officer noticed that Humphries patted his waist, and the officer suspected that Humphries was instinctively feeling for his weapon.
The officers stopped their patrol car about 20 feet from Humphries. When they got out of the car, they smelled a strong odor of marijuana. One officer noticed out of the corner of his eye that Humphries turned quickly and walked rapidly away from the officers. The officer followed Humphries, asking him to stop, saying to him that he needed to talk to him. Humphries did not respond and continued to walk away quickly.
The officer quickened his step to catch up, and once he was within 10 feet of Humphries he smelled "the same strong odor of marijuana . . . coming off of [his] person," and the officer again instructed Humphries to stop. Humphries ignored the officer and began to walk up to a house, where he knocked on the door.
The officer paused at the foot of the stairs of the house and noticed that the smell of marijuana was still strong and was coming from Humphries. When someone opened the door, Humphries walked in, defying the officer's command that he stop and not enter the house. The officer followed Humphries and arrested him.
The officer took Humphries outside and smelled the odor of marijuana on his breath. He patted him down and recovered a 9mm semiautomatic handgun from Humphries's waistband. The officer then conducted a full search incident to arrest, and found 26 Percocet tablets and a small amount of crack cocaine in his pockets. He charged Humphries with possession of Percocet with intent to distribute, simple possession of Percocet, possession of crack cocaine, and possession of a firearm in furtherance of drug trafficking under federal law.
Before trial, Humphries moved to suppress the evidence, contending that the officer did not have probable cause to arrest him, but conceded that he may have had reasonable suspicion to stop and question him. The federal district court granted Humphries's motion and suppressed the evidence, but the Fourth Circuit Court of Appeals reversed that ruling.1
The appellate court stated that it has "repeatedly held that the odor of marijuana alone can provide probable cause to believe that marijuana is present in a particular place."2 The court went on to give examples of its prior rulings that included one in which the smell of marijuana emanating from a "properly stopped vehicle" constituted probable cause to justify a search of the automobile.3 Other examples included a 1974 case in which officers saw boxes inside a van and smelled marijuana, permitting the seizure of the boxes,4 and another where the strong smell of marijuana coming from an open apartment door "almost certainly" provided the officer with probable cause to believe that marijuana was present in the apartment.5
Marijuana Odor as Component of Totality of Circumstances
In Humphries the court acknowledged that "[w]hile smelling marijuana does not assure that marijuana is still present, the odor certainly provides probable cause to believe that it is."6 But this probable cause, or even knowledge of the presence of marijuana, does not in itself authorize the police to search any place or arrest any person in the area. The police must have additional factors to "localize" or "particularize" the placement of the marijuana to justify a search or arrest.7
To substantiate a warrantless search, "the question is whether the totality of the circumstances is sufficient to warrant a reasonable person to believe that contraband or evidence of a crime will be found in a particular place."8 When considering the legality of a warrantless arrest, one considers "whether the totality of the circumstances indicate to a reasonable person that a 'suspect has committed, is committing, or is about to commit' a crime."9 But in either instance, the "quantum of facts required for the officer to search or seize is probable cause" for either a search or seizure.10
The officer had probable cause to arrest Humphries because he recognized the odor of marijuana and was able to "localize its source," namely, Humphries. In addition, there were other factors that strengthened the officer's conclusion that probable cause existed, including Humphries's evasive conduct, his apparent check for a weapon, and the fact that the encounter took place in an area known for drug trafficking.11
Officer Experience and Training in Drug Detection Is Key
The ability of an officer to explain and justify the accuracy of his perceptions is important when he or she relies on those perceptions to formulate probable cause. For instance, a Florida court held that a police officer had probable cause to search a vehicle after smelling burnt marijuana, in part because he had 20 years of experience and had smelled marijuana hundreds of times.12
Where Georgia police went to talk to occupants of a car outside a convenience store and smelled marijuana, their subsequent search of the vehicle was justified. The court found that a trained police officer's ability to identify the odor of burning marijuana constitutes sufficient probable cause to support the warrantless search of a vehicle, as long there is evidence that he in fact was capable of recognizing the odor.13
When officers in Kansas smelled burnt marijuana emanating from a car stopped at a checkpoint, the court held that they had probable cause to search the car and all containers in the car that may have contained marijuana. Here, the odor of marijuana provided suspicion that a crime had been committed and that the evidence of the crime was located within the vehicle.14
But when a police officer cannot prove that he smelled marijuana or that the smell was emanating from a particular place, he cannot reasonably conclude that probable cause existed.15 One court has held that an officer may only discern probable cause from the smell of burnt or raw marijuana if he can determine with reasonable accuracy the point in time when the marijuana was smoked. In that case, because the officer had not been trained in "determining the length of time a residual odor or marijuana has been present" it was not reasonable for him to believe that the vehicle contained marijuana.16
The Supreme Court and the Sense of Smell
The Supreme Court has long recognized the value of an officer's sense of smell in detecting the possible commission of a crime or identifying evidence of a crime. In 1932 the Court held that "prohibition officers may rely on distinctive odors as a physical fact indicative of a possible crime."17 Likewise, the distinctive odor of burning opium detected by an affiant qualified to recognize it was a sufficient basis on which a magistrate could issue a warrant.18 And a qualified officer's detection of the smell of fermenting mash in a location was a "very strong" factor in establishing probable cause for the issuance of a warrant.19
The Supreme Court has said that the standard for probable cause cannot, and should not be, defined with precision or quantification. Whether it exists depends on the specific facts and variables of each circumstance. Officers must rely on each of their five senses, plus a good dose of common sense and knowledge that comes from experience, in determining when probable cause exists. Likewise, they must be able to articulate and explain each of the facts they took into account, and why each fact or circumstance contributed to their conclusion that probable cause existed so as to justify a search or seizure. And it helps if they have a good sense of smell. ■