The U.S. Supreme Court has granted petitions of the State of Florida in Florida v. Jardines, Docket No. 11-564, and Florida v. Harris, Docket No. 11-817, setting the stage for the court’s first major police canine decisions in seven years. Both cases are set for argument in the 2012 October term. In Jardines, the court will consider whether probable cause is needed to conduct a front-door sniff. In Harris, the court will consider whether, to establish probable cause for a vehicle search following a dog’s alert, the prosecution must present complete field records for the dog, not just its training and certification records.

Narcotics detection dogs are trained to detect the odors of common illicit drugs including marijuana, heroin, cocaine and methamphetamine. Such dogs use their acute olfactory ability to locate these target odors and then signal their handlers with an alert when such an odor is present. The dog first demonstrates an obvious behavior change such as an abrupt head turn, change of pace, tail movement, hair raising etc. This action is followed by a trained final response which may be sitting, staring, lying down (passive), or barking or scratching (active or aggressive). Together the obvious behavior change and the trained final response comprise an alert, though the term is sometimes applied to a specific change in behavior or a final response alone.

Prior Sniff Cases

The cases the Supreme Court will hear this fall will address issues not resolved in its major canine decisions. In U.S. v. Place, 462 U.S. 696 (1983), the court held that temporarily detaining luggage on reasonable suspicion for a sniff by a well-trained narcotics detection dog was not a search under the Fourth Amendment. The scope of the investigative detention, however, had to be properly limited, and the court found that the 90-minute detention involved in the case was too long and violated the defendant’s Fourth Amendment rights. The Court therefore reversed Place’s conviction. Justice Sandra Day O’Connor described the canine sniff as sui generis, unlike any other “investigative procedure that is so limited both in the manner in which the information is obtained and in the content of the information revealed by the procedure.”

In Illinois v. Caballes, 543 U.S. 405 (2005), the Supreme Court, in an opinion by Justice John Paul Stevens, held that a sniff conducted during a lawful traffic stop that reveals no information other than the location of a substance no individual has a right to possess (illegal drugs) does not violate the Fourth Amendment. The court noted that the trial judge had determined that “the dog alert was sufficiently reliable to provide probable cause to conduct the search.” The initial seizure of the defendant was based on probable cause of a traffic violation, but the sniff could be conducted without reasonable suspicion.

In Place, the court had held that allowing a “well-trained narcotics detection dog” to sniff luggage was not a search. The court did not specify what would make a dog “well-trained” or whether certification at some prior point means that a dog has been trained sufficiently that all subsequent sniffs it conducts provide probable cause for a search. Should subsequent refresher training and deployment records be evaluated in determining whether a dog has maintained an adequate training level? These issues will be considered in Harris.

In Caballes, the court held that a sniff during a lawful traffic stop did not require probable cause or even reasonable suspicion. The court did not state whether the same lack of an evidentiary threshold would apply to other environments, such as a sniff at the front door of a house where there might be marijuana growing. That issue will be considered in Jardines.


The Jardines case began with an anonymous tip that Joelis Jardines was growing marijuana in his home. The police followed up on the tip over a month later by going to Jardines’ house with “multiple police vehicles, multiple law enforcement personnel,” and a narcotics detection dog and handler. The dog gave an alert at the front door. Some of the law enforcement personnel remained at the scene while others left and obtained a warrant. The house was searched, and growing marijuana plants were found. On appeal, the Florida Supreme Court determined “the warrantless ‘sniff test’ that was conducted at the front door of the residence… was an unreasonable government intrusion into the sanctity of the home and violated the Fourth Amendment.”

The State of Florida seeks to have the Florida Supreme Court reversed, arguing that probable cause is not required to bring a dog to the front door of a suspected grow house. Most state courts that have dealt with the issue have determined that reasonable suspicion is required to conduct a front-door sniff, though neither side in Jardines is suggesting this threshold. See, e.g., New York v. Dunn, 77 N.Y.2d 19, 564 N.E.2d 1054 (1990) (sniff at apartment door was search under New York State Constitution); Nebraska v. Ortiz, 600 N.W.2d 805 (1999) (warrant constitutionally defective because officers did not have reasonable suspicion); Fitzgerald v. Maryland, 864 A.2d 1006 (2004) (reasonable suspicion was present, as in Place); Hoop v. Indiana, 909 N.E.2d 463 (Ct.App.2009) (sniff of a private residence requires reasonable suspicion).

Some courts have found that Place and particularly Caballes mean that the location of a sniff is irrelevant because a person has no legitimate privacy interest in the possession of contraband. See, e.g., Michigan v. Jones, 755 N.W.2d 224 (2008) (no reasonable expectation of privacy at entrance to property open to the public where canine was lawfully present); Rodriguez v. Texas, 106 S.W.3d 224 (Ct. App. 2003) (no reasonable expectation of privacy outside the front door of defendant’s home because area was not enclosed, was used as the home’s main entrance, and was not shielded from observation by passers-by). But see U.S. v. Peter, 2012 WL 1900133 (N.D. Ind. 2012) (rejecting reasonable suspicion and probable cause, but requiring “some suspicion to justify the intrusion” of sniffing at a front door).

Few courts besides the Florida Supreme Court have required probable cause for a front door sniff. In U.S. v. Thomas, 757 F.2d 1359 (2d Cir. 1984), the U.S. Court of Appeals for the Second Circuit distinguished the luggage sniff in Place by noting that the defendant’s “heightened expectation of privacy inside his dwelling” made the sniff into a search, which, without a warrant, violated the Fourth Amendment. The evidence was not excluded, however, because the warrant, issued subsequent to the sniff, was executed in good faith. A heightened privacy expectation of a home has often been correlated with the legal concept of curtilage, including recently by the Supreme Court in U.S. v. Jones, 132 S.Ct. 945 (2012) (majority noting that “an open field, unlike the curtilage of a home…is not one of those protected areas enumerated in the Fourth Amendment.”).

A prior Florida case, Florida v. Rabb, 881 So.2d 587 (Ct. App. 2004), reversed and remanded, 544 U.S. 1028 (2005), on remand, 920 So.2d 1175 (Ct. App. 2006), cert. denied, 549 U.S. 1052 (2006), had also found a probable cause requirement for a front door sniff, and the U.S. Supreme Court had granted certiorari, then reversed and remanded for reconsideration in light of Caballes, which it had just decided. On remand, the Florida appellate court, noting “significant place and situation differences from Caballes,” did not retreat from its prior conclusion that probable cause was required for a front door sniff. The Supreme Court declined to grant certiorari a second time.


In Harris, a Liberty County Sheriff’s officer deployed a drug detection dog, Aldo, during a traffic stop for an expired tag. Aldo gave an alert at the door handle of the driver’s side and the subsequent search revealed pseudoephedrine pills, a precursor to methamphetamine, in a toolbox inside the vehicle. The Florida Supreme Court held that Caballes had resolved that the sniff was not a search, but reversed because the prosecution had not produced evidence sufficient to establish Aldo’s reliability.

Aldo was trained and certified to detect marijuana, cocaine, ecstasy, heroin, and methamphetamine. Officer William Wheetley, the handler, maintained field records only when an arrest was made, but did “not keep records of Aldo’s alerts in the field when no contraband is found.” The trial court denied a motion to suppress and found probable cause for the search. An appellate court affirmed, and the Florida Supreme Court accepted the case based on a conflict between the state’s appellate courts. Three districts in the state had concluded that if a defendant wished to challenge the reliability of a dog, it was the defendant’s burden to introduce field performance records of the dog or other evidence, such as expert testimony. The Second District Court of Appeals, however, in Florida v. Matheson, 870 So.2d 8 (2d DCA 2003), had held that training and certification standing alone only provided a “mere suspicion” and were insufficient to give probable cause for a search based on a dog’s alert.

The Florida Supreme Court in Harris determined that establishing probable cause required assessing the dog’s reliability. The court said that this assessment requires an evaluation of the dog’s training records, certification status, and success in the field, as well as an evaluation of the handler’s experience and training. The court said that a dog’s alert by itself “does not indicate that drugs are probably present in the vehicle” if the dog is not a reliable detector of drugs. Only when the dog is determined to be reliable can its alert “indicate to the officer that there is a fair probability that contraband will be found.”

The court held that the prosecution bore the burden of establishing probable cause, and that to do so it had to present records and evidence necessary to allow the trial court to evaluate the reliability of the dog. Training and certification were not enough to establish reliability because “there is no uniform standard for training and certification of drug-detection dogs.” Further, the state should keep and present records of the dog’s performance including alerts where contraband the dog was trained to detect was found and alerts where contraband the dog was trained to detect was not found. Because only successes were being recorded by Wheetley, “it is impossible to determine what percentage of time Aldo alerted and no contraband was found following a warrantless search of the vehicle.”

In deciding Harris, the U.S. Supreme Court may refer to a widely publicized scientific study, which raised the possibility that cueing—unintentional acts of the handler that signal a dog to give an alert—may be far more prevalent than previously recognized. The study found that canine detection teams going through a portion of a church gave alerts in 85 percent of the runs, but did not alert in only 15 percent of the runs. All alerts were, according to the researchers, false because there were no drugs or drug odors present. Only one dog made no mistakes; most made false alerts. All teams were certified by a law enforcement agency. Lit, Schweitzer, and Oberbauer (2011). “Handler Beliefs Affect Scent Detection Dog Outcomes,” Animal Cognition, Vol. 14 Issue 3 (2011 Springer Publishing).


Decisions in Jardines and Harris will provide guidance for many situations in which evidence is produced by canine work. In Jardines, the Supreme Court will determine whether there is an evidentiary threshold before a front-door sniff can be conducted. In Harris, the court will have to consider whether performance in the field is essential in determining whether a dog is reliable. Each of these issues could be resolved in a number of ways, but whatever approach the Supreme Court chooses, the current law in some jurisdictions will not stand and police practice will have to change significantly.

John J. Ensminger practices in Stone Ridge, N.Y., and is the author of “Police and Military Dogs” (Taylor & Francis, 2011). L.E. Papet is the executive director of K9 Resources in Cincinnati, Ohio.