Florida v. Harris

LII note: The U.S. Supreme Court has now decided Florida v. Harris.


Did the Florida Supreme Court err in creating an additional evidentiary standard that the state must satisfy before an alert from a well-trained drug-detection dog may suffice to establish probable cause?

Oral argument: 
October 31, 2012
Court below: 

Officer Wheetley stopped Clayton Harris’s truck for expired tags and searched the vehicle after his drug-detection dog alerted to the driver-side door handle. Officer Wheetley recovered precursors to methamphetamine, and at trial Harris alleged that Officer Wheetley did not have probable cause, or a reasonable basis, to search and violated his Fourth Amendment rights. On appeal, Harris argues that training alone cannot establish a dog’s reliability because there are no standard certification standards for drug-detection dogs, and dogs are likely to be influenced by outside factors that could affect their reliability. The State of Florida asserts that certification of a dog should be sufficient to prove reliability, and to provide adequate basis for a search. This decision implicates concerns of individuals’ right to privacy in their possessions and raises concerns of costs associated with increased evidentiary burdens in drug possession cases, which could hamper the states’ ability to prosecute drug offenders.

Questions as Framed for the Court by the Parties 

Whether the Florida Supreme Court has decided an important federal question in a way that conflicts with the established Fourth Amendment precedent of this Court by holding that an alert by a well-trained narcotics detection dog certified to detect illegal contraband is insufficient to establish probable cause for the search of a vehicle?


In June 2006, Officer William Wheetley stopped Clayton Harris’s truck because its tags had expired. As he approached, Officer Wheetley noticed that Harris appeared jittery and anxious, and he could see an open beer can in the cup holder. Officer Wheetley requested to search the truck, and when Harris refused, Officer Wheetley sent Aldo, his drug-detection dog, to conduct a “free-air sniff.” Aldo was trained and certified to detect several drugs including methamphetamine. At the time of this traffic stop, Aldo had been certified for over two years, and he and Officer Wheetley had been partners for one year. Officer Wheetley had trained Aldo in drug-detection for four hours per week, and they complete a forty-hour training seminar together annually.

After his “free-air sniff” of the outside of the truck, Aldo alerted to the driver-side door handle. After the alert, Officer Wheetley searched Harris’s truck and found over two-hundred pseudoephedrine pills, eight-thousand matches, and muratic acid. Officer Wheetley recognized these materials as precursors to methamphetamine and arrested Harris. During the arrest, Harris voluntarily revealed that he had been cooking methamphetamine for approximately one year, had most recently done so two weeks prior to the arrest, and could not go more than a few days without using it.

The State of Florida charged Clayton Harris with possession of pseudoephedrine with the intent to use the chemical to make methamphetamine, in violation of Florida Statute § 893.149(1)(a). Harris moved to suppress the items recovered during the search, alleging that Officer Wheetley did not have probable cause to conduct the search. During the suppression hearing in the Circuit Court of Liberty County, Florida, Harris introduced evidence to support his position that Aldo was an unreliable drug-detection dog. Harris testified that two months after the initial stop, Officer Wheetley again stopped Harris for a traffic violation and deployed Aldo. Aldo again alerted to the driver-side door but this time Officer Wheetley did not recover any contraband.

Officer Wheetley testified that Aldo had a good success rate in training and always received a satisfactory performance level, but indicated that he does not keep a record of Aldo’s field accuracy. Officer Wheetley also testified that Aldo might alert to residual odors of narcotics, but was unsure how long the odor would remain on an object after a person with drug odor on their hand touched it.

The trial court held that Officer Wheetley had probable cause to search the truck based on the expired tag, open container, Harris’s behavior, and an alert by a trained and certified drug-detection dog. The Florida First District Court of Appeal affirmed the lower court’s holding.

The Florida Supreme Court reversed, holding that the prosecution did not meet its burden of establishing that Officer Wheetley had probable cause to search, and accordingly the evidence recovered pursuant to the search should have been suppressed. In reaching this result, the court developed a test for probable cause in cases involving drug-detection dogs. The court held that the prosecution must present evidence of the dog’s training and certification, an explanation of the training and certification, field performance records, and evidence of the officer’s experience and training concerning the handling of drug-detection dogs.


The Fourth Amendment protects individuals from unreasonable searches and seizures. Though the Supreme Court has held that an officer need not obtain a warrant before searching a vehicle, that officer must have probable cause to search. An officer has probable cause to search a vehicle if under the totality of the circumstances, a reasonable person in the officer’s situation would believe that there was a substantial chance that the search would lead to discovery of contraband. The Florida Supreme Court developed an evidentiary standard to establish probable cause that applies in cases in which drug-detection dogs are deployed. The court held that in order for a drug-detection dog’s alert to establish probable cause, the prosecution must present evidence of the dog’s training and certification, an explanation of the training and certification, field performance records, and evidence of the officer’s experience and training concerning the handling of drug-detection dogs. Emphasizing that the probable cause standard is a flexible one, Petitioner Florida argues that an alert by a well-trained drug-detection dog is sufficient to create probable cause to search a vehicle. Respondent Clayton Harris counters that because of the lack of standard training for drug-detection dogs, handler error, and the potential for “false alerts”, the animal’s reliability in detecting drugs must first be proven in order for the alert to constitute as probable cause.

Probable Cause Standard

Florida emphasizes that the probable cause standard does not require certainty and should be regarded flexibly. Florida points out that the Supreme Court of the United States has declined to mechanize the probable cause standard, and has repeatedly required courts to consider the reasonableness of the officer’s actions in light of the totality of the circumstances. Accordingly, Florida argues that the rigid evidentiary standard that the Florida Supreme Court developed in this case runs contrary to the holdings of prior cases regarding the Fourth Amendment. Florida iterates that the standard must be based on judgments by the police officer at the time of the occurrence and cannot be reduced to mechanical formulas. Moreover, Florida argues that the most qualified person to assess the reliability of the trained dog is the officer who handles the dog. Accordingly, Florida contends that if a drug-detection dog is well trained, then the dog’s alert creates probable cause to search a vehicle, and no additional evidence is necessary. Florida defines a well-trained dog as one who is either certified or has a successful training record.

Harris counters, arguing that the Florida Supreme Court’s evidentiary standard does not conflict with Supreme Court precedent. Harris asserts instead that the evidentiary standard increases the likelihood that the court will consider all relevant circumstances in their analysis, thereby better applying the totality of the circumstances test. Further, Harris contends that a drug-detection dog’s alert to its handler is equivalent to an informant’s anonymous tip to the police. Harris explains that the Supreme Court has held that an anonymous tip without additional verified and specific details of criminal activity cannot create probable cause. Harris argues that like an anonymous tip, a dog’s alert cannot be fully corroborated before the officer conducts a search. Accordingly, Harris contends that verification of a dog’s reliability must be given in order to justify a vehicle search, and the additional evidence required by the Florida Supreme Court provides this verification.

Whether a Dog’s Alert Establishes Probable Cause

Harris emphasizes the case-by-case nature of this test and points out that part of this case-by-case analysis should be to assess the individual skills and reliability of each drug-detection dog. Harris argues that because there is no uniform standard of training and certification for drug-detection dogs, the mere fact that a dog has been trained and certified is not conclusive. Accordingly, Harris contends that in order to determine if an officer has acted reasonably, the court must assess the reliability of the drug-detection dog. Harris states that the only way to assess a dog’s reliability in drug detection is to examine the dog’s records in the field by reviewing past performance. Far from being a burden, Harris argues that record-keeping by police officers is standard; requiring the officer to keep a record of each deployment of the officer’s drug-detection dog would involve little additional effort. In addition, Harris points out that several courts have already considered a dog’s field records while assessing the dog’s reliability.

Florida argues that certification or other evidence of a dog’s proficiency in drug detection is sufficient to establish a dog’s reliability. Moreover, Florida contends that a court assessment of each individual dog’s record would amount to putting the dog on trial every time a case arises as a result of dog detecting drugs. Florida argues that the comparison between an anonymous informant and a drug-detection dog is unfounded because the reason an anonymous tip requires additional verification is due to an informant’s potential ulterior motives. By contrast, Florida argues, law enforcement officials have a strong incentive to ensure the reliability and proficiency of the dogs. Further, Florida asserts that the court is not in the best position to determine the reliability of the dog, and police officers should be able to rely on their own judgment. Accordingly, Florida argues that if a dog is well trained, then the dog’s alert creates probable cause to search a vehicle. Additionally, Florida argues that a dog’s training records are more persuasive than records of a dog’s performance in the field. Florida explains that there is no way to conclusively determine in a field setting whether or not the dog correctly alerted the police officer to the presence of narcotics. That is, if a search does not yield contraband, it could be due to a number of factors, just one of which is that the dog’s alert was a false positive.

Potential Threats to a Drug-detection Dog’s Reliability

Harris argues that there are two primary problems with relying upon even a well-trained drug-detection dog to create probable cause to search a vehicle for contraband. First, Harris contends that drug-detection dogs are susceptible to respond to over-cuing from their handlers. In support of this position, Harris cites a field study that he argues is indicative of over-cuing by handlers, and the tendency of drug-detection dogs to respond to those cues. In this way, Harris argues, any prejudice that a police officer may have could lead to an alert from the officer’s drug-detection dog. Second, Harris argues that because a drug-detection dog may detect odors of narcotics in legal substances, it is not possible to determine how likely a search is to lead to recovery of contraband. Harris cites examples of dogs alerting to individuals who were free of contraband due to these confounding odors.

Florida argues that these potential threats to a dog’s reliability do not negate probable cause. Florida explains that probable cause does not require certainty, but instead deals with probabilities. Florida argues that law enforcement interests provide incentive to ensure a dog’s reliability in detecting drugs, so an officer is unlikely to send a dog that is not properly trained or not reliable into the field. Additionally, Harris argues that the potential of an alert to a residual odor does not negate probable cause to search, because the presence of a residual odor of narcotics increases the likelihood that contraband is present, including drug paraphernalia. Further, Harris contends that the possibility of a “false alert” has always been present when dealing with dogs in the field, but that does not detract from their usefulness.


This decision will clarify the circumstances under which an alert by a trained drug-detection dog would constitute probable cause sufficient to justify the warrantless search of a vehicle under the Fourth Amendment. The State of Florida asserts that a drug-detection dog’s successful completion of a professional training program is sufficient to establish the dog’s reliability, so a trained dog’s sniff would constitute probable cause. Florida argues that routinely engaging in a more probing inquiry into a dog’s reliability would impose a rigid and undue burden on law enforcement. Clayton Harris contends that mere certification is insufficient to establish reliability due to lack of uniform standards among dog-training professionals, and that requiring field performance records to establish reliability is not unduly burdensome.

False Alerts and Handler Cueing

Harris contends that the potential for false alerts by drug-detection dogs constitutes an impermissible level of error when dealing with Fourth Amendment rights. The National Association of Criminal Defense Lawyers (“NACDL”) asserts that drug-detection dog handlers often approach vehicles after forming subjective expectations regarding the presence of narcotics. Because dogs are frequently attuned to the emotions of their handlers, these subjective expectations might unduly influence the dog’s alerting behavior. The Rutherford Institute argues that due to the error rate among trained dogs and the potential for handler cueing, allowing an alert by a trained dog to satisfy probable cause would give law enforcement officials essentially unfettered discretion to conduct searches.

However, Florida cites two strong incentives for law enforcement officers to train their dogs well so as to avoid false alerts: first, false alerts would waste officers’ time; and second, false alerts would unnecessarily expose officers to the inherent dangers of a roadside stop. Additionally, the United States argues that a search which does not yield contraband is not a false alert, but merely an unconfirmed one, and therefore does not bear negatively on a dog’s reliability.

Undue Evidentiary Burden

Florida cautions that when training and certification are not enough to establish reliability of a drug-detection dog, suppression hearings can become full-blown trials on the technical aspects of the dog’s training. Virginia and supporting states posit that such evidentiary requirements would lead to endless litigation at suppression hearings. Such side trials would strain judicial resources and place onerous burdens on law enforcement to keep detailed records of a dog’s field performance. The United States adds that these side trials would also undermine the certainty that allows law enforcement officers to reasonably rely on alerts by trained drug-detection dogs.

Harris insists that requiring law enforcement to present such information might actually lead to fewer suppression hearings, because defendants would be less likely to attempt to suppress evidence if they were aware that a particular dog has a strong track record. The NACDL notes that many law enforcement agencies already keep field performance records of their drug-detection dogs, and Harris adds that the government is the only party capable of keeping track of such records.

Public Safety Versus Personal Privacy

Virginia and supporting states argue that a rule mandating constant record-keeping by law enforcement might deter the use of drug-detection dogs. Florida adds that this chilling effect on the use of drug-detection dogs would in turn restrict law enforcement’s ability to prevent the traffic of drugs within the state’s borders. More broadly, Florida also points out that releasing guilty defendants from responsibility would impose substantial costs on both society and law enforcement. Florida further points out that because dogs are also trained to detect other contraband such as human remains, pirated DVDs, and illegal fruits and vegetables, this mere certification standard for contraband-detection dogs could also extend to warrantless searches in those instances as well.

In contrast, Harris identifies social cost in terms of those innocent motorists who will be subject to intrusive searches based on false alerts by drug-detection dogs. Additionally, the Electronic Privacy Information Center anticipates this decision’s implications for electronic privacy and warrantless searches of digital media suspected of containing contraband.


In this case, the Supreme Court will decide whether the Florida Supreme Court’s evidentiary standard set forth for the Fourth Amendment in drug possession cases which involve the use of a drug-detection dog contravenes its established precedent. The State of Florida argues that it does, contending that the evidentiary standard required by the court is in essence a mechanization of the historically loose case-by-case probable cause inquiry. Florida asserts that the court is not in the best position to assess the reliability of the dog, and that an alert from a well-trained drug-detection dog would create probable cause to search. Clayton Harris disagrees, arguing instead that the evidentiary standard is akin to the extra evidence that precedent requires in cases involving anonymous informants. Harris argues that an individual determination of the reliability of each drug-detection dog is necessary to determine whether an officer had probable cause to search the vehicle. This decision implicates concerns of individuals’ right to privacy regarding their possessions.

Edited by 


Additional Resources 

E. Duncan Getchell, Jr. & Michael Brady, Florida Supreme Court Erred in Drug Dog Ruling, JURIST-Hotline, Apr. 23, 2012, http://jurist.org/hotline/2012/04/getchell-brady-florida-canines.php.