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Florida v. Harris

Concerning the Reliability of an Alert by a Narcotics-Detection Dog

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  • EPIC Files Amicus in Case Concerning Government Searches and Google's Email Screening Practices: EPIC has filed an amicus brief with the U.S. Court of Appeals for the Sixth Circuit in United States v. Miller, arguing that the Government must prove the reliability of Google email screening technique. The lower court held that law enforcement could search any images that Google's algorithm had flagged as apparent child pornography. EPIC explained that a search is unreasonable when the government cannot establish the reliability of the technique. EPIC also warned that the government could use this technique "to determine if files contain religious viewpoints, political opinions, or banned books." EPIC has promoted algorithmic transparency for many years. EPIC routinely submits amicus briefs on the application of the Fourth Amendment to investigative techniques. EPIC previously urged the government to prove the reliability of investigative techniques in Florida v. Harris. (Oct. 18, 2018)
  • Presidential Science Advisors Challenge Validity of Criminal Forensic Techniques: According to an upcoming report by the President’s Council of Advisors on Science and Technology, much of the forensic analysis in criminal trials is not scientifically valid. The report, to be released this month, attacks the validity of analysis of evidence like bite-marks, hair, and firearms. The "lack of rigor in the assessment of the scientific validity of forensic evidence is not just a hypothetical problem but a real and significant weakness in the judicial system,” wrote the council. The Senate Judiciary Committee held hearings in 2009 and 2012 to discuss the need to strengthen forensic science, and Sen. Patrick Leahy (D-VT) introduced a forensic reform bill in 2014. EPIC has pursued FOIA requests on the reliability of proprietary forensic techniques. EPIC also filed a brief on the reliability of novel forensic techniques in the Supreme Court case Florida v. Harris. (Sep. 8, 2016)
  • Supreme Court Limits Traffic Stop Searches: The Supreme Court issued its opinion today in Rodriguez v. United States, a Fourth Amendment case involving the use of a drug-detection dog during a traffic stop. The Court found that it was unlawful for a police officer to detain a driver for the sole purpose of conducting a "sniff" test after the traffic stop was completed. The Supreme Court rejected the Government's argument that extending the stop to wait for a dog to search for drugs was "only a de minimis" intrusion of Fourth Amendment rights. EPIC previously filed an amicus brief in Florida v. Harris, a similar case before the Supreme Court concerning the use of canines for drug detection, arguing that the Fourth Amendment requires routine testing of investigatory techniques to assess reliability and establish reasonableness. (Apr. 21, 2015)
  • U.S. Supreme Court Tosses Out North Carolina Lifetime GPS Tracking: Today the U.S. Supreme Court issued a per curium opinion vacating the decision of the North Carolina Supreme Court in Grady v. North Carolina. Grady challenged a court order requiring a "satellite-based [GPS] monitoring program for the duration of his natural life." The North Carolina court ruled that this was not a Fourth Amendment search. However, the U.S. Supreme Court tossed that ruling aside, finding it contrary to recent decisions in United States v. Jones and Florida v. Jardines. EPIC filed an amicus brief in Jones, joined by many leading technical experts and legal scholars. The Court held in that case that continuous GPS tracking constituted a search. (Mar. 30, 2015)
  • DOJ Reverses Course on Forensic Evidence Committee After Federal Judge Resigns in Protest: The Department of Justice has reversed a decision to limit oversight of scientific evidence after a federal judge threatened to resign in protest. The National Commission on Forensic Science, established by the DOJ, was charged with improving the reliability of forensic science but the Justice Department appeared ready to make a recommendation contrary to the Commission's purpose. Senator Patrick Leahy (D-VT) has urged better oversight of forensic evidence in the criminal justice system. EPIC also asked the Supreme Court in an amicus curiae brief in Florida v. Harris to look more closely at investigative techniques that help establish probable cause. EPIC argued that courts should ensure that techniques are adequately tested to ensure the accuracy and validity of results. The dispute over the recommendations of the National Commission on Forensic Science reflect a similar concern. (Jan. 30, 2015)
  • Supreme Court Lets Stand Fourth Amendment Protections At the Border: This week the Supreme Court declined to review the decision of the Ninth Circuit in United States v. Cotterman, leaving in place expanded Fourth Amendment protections for searches occurring at the U.S. border. In Cotterman, the federal appeals court held that the Fourth Amendment requires a border agent to have reasonable suspicion before using forensic tools to search laptops, cameras, and other digital devices. The court emphasized that the "comprehensive and intrusive nature of the forensic examination" is the key factor in triggering greater Fourth Amendment scrutiny. EPIC has previously argued that advanced traveler screening methods should only be employed subject to privacy protections. For more information, see EPIC: Traveler Privacy, EPIC: Florida v. Jardines, and EPIC: Amicus Curiae briefs. (Jan. 15, 2014)
  • Supreme Court Holds Dog Sniff at Doorway is a Search: The Supreme Court ruled today in Florida v. Jardines that the use of a drug-sniffing dog to investigate the front door of a home was a “search” within the meaning of the Fourth Amendment. “That the officers learned what they learned only by physically intruding on Jardines’ property to gather evidence is enough to establish that a search occurred,” Justice Scalia concluded. Justice Kagan, joined by Justices Ginsburg and Sotomayor, wrote a concurrence that explained that the case could have also been resolved by examining Jardines’ privacy interests. In Justice Kagan’s view, the use of device “not in general public use” to “explore the details of the home” violates a reasonable expectation of privacy and is therefore a search. EPIC filed an amicus brief in a related Supreme Court case, decide earlier this year. For more information, see EPIC: Florida v. Jardines and EPIC: Florida v. Harris. (Mar. 26, 2013)
  • "Sniff up to snuff," says Supreme Court in Drug-detecting Dog Case: The Supreme Court ruled today in Florida v. Harris that the police may use drug detection dogs to conduct searches without a warrant even when the dog finds drugs they are not trained to detect. The Florida Supreme Court had ruled that the search was unlawful because the State failed to provide field performance records to establish the dog's reliability. The U.S. Supreme Court unanimously reversed in an opinion written by Justice Elena Kagan, rejecting the Florida court's "inflexible checklist" of necessary evidence in favor of a more flexible, "common-sensical standard." EPIC filed an amicus curiae brief in the case, arguing that "investigative techniques should be used based on research, testing, and data indicating reliability." EPIC cited a recent National Academy of Sciences report highlighting the lack of reliable standards for investigative techniques. Late last week, the Department of Justice announced a new initiative to improve forensics reliability. For more information, see EPIC: Florida v. Harris. (Feb. 19, 2013)
  • EPIC Supreme Court Brief: Investigative Techniques are Not Infallible: EPIC has filed an amicus brief with the US Supreme Court, arguing that new "investigative techniques should be subject to close scrutiny by the courts." EPIC submitted the brief in Florida v. Harris, a case involving a car search in response to an "alert" by a drug detection dog. The Florida Supreme Court held that a law enforcement agent relying on such an "alert" must produce evidence to support the reliability of the detection technique. Filing in support of the Florida decision, EPIC argued that new investigative techniques, such as terahertz scanners, airport body scanners, and digital intercept devices, raise similar concerns about reliability. EPIC described a growing consensus among legal scholars and technical experts about the need to improve the reliability of many forensic techniques.  "The 'perfect search,'" EPIC wrote, "like the 'infallible dog,' is a null set." For more information, see EPIC: Florida v. Harris and EPIC: Florida v. Jardines. (Aug. 30, 2012)
  • Supreme Court to Hear Case About Enhanced Search Techniques: The US Supreme Court has decided to review Florida v. Jardines, a case that addresses whether a dog sniff at the front door of a home is a search that requires probable cause. This case follows Illinois v. Caballes, a 2005 case in which the Court held that a dog sniff around a car during a routine traffic stop was not a search. The Florida Supreme Court ruled that Caballes was inapplicable in the case, and that a dog sniff in front of a home is a Fourth Amendment search. This case also implicates the government's use of "enhanced" investigative techniques that are designed to detect contraband. Because these techniques are imperfect and also allow the government to search for material that is not illegal, EPIC has argued that a Fourth Amendment probable cause standard should apply. For more information, see EPIC: EPIC v. DHS (Airport Body Scanners). (Jan. 6, 2012)

Question Presented

  • Whether an investigative technique that law enforcement asserts reliably identifies the presence of contraband is sufficient to satisfy the probable cause requirement of the Fourth Amendment and thereby allows routine warrantless searches.


In Florida v. Harris, the Supreme Court will address the reliability of an "alert" from a trained narcotics-detection dog. Specifically, the Court will determine under what circumstances an alert is sufficient to establish probable cause for a subsequent search. The lower court ruled that the fact that a drug-detection dog has been trained and certified to detect narcotics, standing alone, is not sufficient to demonstrate the reliability of the dog for purposes of determining probable cause for a search.

In Harris, the defendant was charged with possession of the listed chemicla psudoephedrine with intent to use it to manufacture methamphetamine. The evidence was gathered during a warrantless search of defendant's truck. The government argued that the search was reasonable because it was conducted subsequent to an "alert" by the officer's drug-detection dog, Aldo. The dog alerted after conducting a "free air sniff" test and a test of the driver's side door handle. The dog was not trained to detect pseudoephedrine. Defendant was later stopped by the same officer, and the same dog alerted again to his driver's side door handle, but the officer discovered no contraband when he searched the vehicle. The Officer admitted at court that the dog can pick up "residual odors" of contraband, which could linger for an unknown amount of time. Thus, the defendant argued, the government must provide evidence to establish the reliability of the dog's alert based on the accuracy of prior alerts. The Florida Supreme Court agreed, holding that "[t]o demonstrate that an officer has a reasonable basis for believing that an alert by a drug-detection dog is sufficiently reliable to provide probable cause to search, the State must present evidence of the dog's training and certification records, ... field performance records (including any unverified alerts), and evidence concerning the experience and training of the officer ..." Harris v. State, 71 So. 3d 756 (Fla. 2011).

Establishing Probable Cause

The Fourth Amendment provides that "[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated." U.S. Const. amend. IV. "[S]earches conducted outside the judicial process, without prior approval by judge or magistrate, are per se unreasonable under the Fourth Amendment - subject only to a few specifically established and well-delineated exceptions." Katz v. United States, 389 U.S. 347, 357 (1967). One such exception to the warrant requirement is the "automobile exception," first established by the United States Supreme Court in Carroll v. United States, 267 U.S. 132 (1925). In Carroll, the Supreme Court held that a warrantless search of a vehicle based upon probable cause to believe that the vehicle contains contraband is not unreasonable within the meaning of the Fourth Amendment. Id. at 149. See also Maryland v. Dyson, 527 U.S. 465, 467 (1999).

The Court has made clear that probable cause "depends on the totality of the circumstances." Illinois v. Gates, 462 U.S. 213, 238 (1983). It exists when "there is a fair probability that contraband or evidence of a crime will be found in a particular place." United States v. Grubbs, 547 U.S. 90 (2006). And when "the facts and circumstances within their (the officers') knowledge and of which they had reasonably trustworthy information [are] sufficient in themselves to warrant a man of reasonable caution in the belief that "an offense has been or is being committed." Brinegar v. United States, 338 U.S. 160, 175-76 (1949). The burden is on the government to demonstrate that the police had probable cause to conduct a warrantless search.

Drug Detection Dogs and the Fourth Amendment

The Supreme Court has held that in certain contexts use of a narcotics-detecting dog to test a parcel or automobile does not require probable cause. In United States v. Place, the Court held that subjecting luggage that was temporarily seized at an airport, based on mere reasonable suspicion that it contained contraband, to a sniff test by a well-trained narcotics-detecting dog was not a "search" under the Fourth Amendment. United States v. Place, 462 U.S. 696, 707 (1983). In Illinois v. Caballes, the Court found that a similar sniff test conducted on the exterior of a car during a routine traffic stop was also not a "search" under the Fourth Amendment. 543 U.S. 405, 409 (2005). See also City of Indianapolis v. Edmonds, 531 U.S. 32, 40 (2000). In both cases, the narcotics dog "alert" was used as the basis for a subsequent search of the luggage and car. The Court found that the test itself did not constitute a "search" because it "[did] not expose noncontraband items that otherwise would remain hidden from public view." Caballes, 543 U.S. at 409 (citing Place, 462 U.S. at 707). The Court assumed in Place, and the Respondent conceded in Caballes, that "the [test] discloses only the presence or absence of narcotics, a contraband item." Place, 462 U.S. at 707. However, the defendant in Harris successfully argued that the reliability of the dog sniff test must be proven by the government in order for the alert to provide probable cause for the subsequent search.

EPIC's Interest in Florida v. Harris

EPIC has argued in the past that the Fourth Amendment probable cause standard should apply in cases where the government uses "enhanced investigative techniques" in an attempt to detect contraband, see EPIC v. DHS (Suspension of the Body Scanner Program), where these techniques are imperfect, ineffective, and likely to lead to the exposure of private in formation (non-contraband) and legal conduct.

The Supreme Court's Decision

On February 19, 2013 the Supreme Court unanimously ruled to overturn the Florida Supreme Court's opinion in Harris. In rejecting the lower court's conclusion that, when a dog alerts, "the fact that the dog has been trained and certified is simply not enough to establish probable cause," and the lower court's focus on the need for "evidence of the dog's performance history," the Supreme Court noted that "[t]he test for probable cause is not reducible to 'precise definition or quantification.'" Slip. Op. at 5. Instead, the Court adopted its traditional "totality of the circumstances" test, and rejected the lower court's "inflexible checklist" approach to reliability. The Court noted the potential pitfalls of false negatives and positives in field performance records, and stressed that "[t]he better measure of a dog's reliability thus comes away from the field, in controlled testing environments." Slip. Op. at 8. But, as the Court emphasized, a defendant "must have an opportunity to challenge such evidence" of reliability. EPIC's amicus brief focused on the need to establish the reliability of future investigative techniques with background research and national standards. In this case, the Court found that "[b]ecause training records established Aldo's reliability in detecting drugs and Harris failed to undermine that showing," the officer had sufficient probable cause based on the dog's alert to the truck handle.

Legal Documents

Supreme Court


Florida Supreme Court


Supreme Court - Non-search Contraband Cases

  • Illinois v. Caballes, 543 U.S. 405 (2005).
  • City of Indianapolis v. Edmond, 531 U.S. 32 (2000).
  • United States v. Jacobsen, 466 U.S. 109 (1984)
  • United States v. Place, 462 U.S. 696 (1983).

Supreme Court - Probable Cause Cases

  • United States v. Grubbs, 547 U.S. 90 (2006).
  • Illinois v. Gates, 462 U.S. 213, 238 (1983).
  • Brinegar v. United States, 338 U.S. 160 (1949).

Other Cases

  • Melendez-Diaz v. Massachusetts, 557 U.S. 305 (2009).
  • Herring v. United States, 555 U.S. 135 (2009).
  • Bond v. United States, 529 U.S. 334 (2000).
  • Arizona v. Evans, 514 U.S. 1 (1995) (O'Connor, J., concurring).
  • Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).
  • United States v. $242,484.00, 351 F.3d 499 (11th Cir. 2003), vacated on other grounds by reh'g en banc, 357 F.3d 1225 (11th Cir. 2004).

Law Review Articles and Books

  • Jane Yakowitz Bambauer, How the War on Drugs Distorts Privacy Law, 64 Stan. L. Rev. Online 131 (2012).
  • Jeffrey Rosen, The Deciders: The Future of Privacy and Free Speech in the Age of Facebook and Google, 80 Fordham L. Rev. 1525 (2012).
  • L. Song Richardson, Police Efficiency and the Fourth Amendment, 87 Ind. L. J. 1143 (2012).
  • NOTE, Jessica Alfano, Interior-Vehicle Sniffs: Reining in the Leash on Drug-dog Sniffs and Searching for the "Search" That Courts Have Yet to Find, 46 New Eng. L. Rev. 519 (2012).
  • Jeff Weiner, Police K-9's and the Constitution: What Every Lawyer and Judge Should Know, 36 APR Champion 22 (April, 2012).
  • Joshua S. Levy, Towards A Brighter Fourth Amendment: Privacy and Technological Change, 16 Va. J.L. & Tech. 499, 501 (2011).
  • Russell D. Covey, Pervasive Surveillance and the Future of the Fourth Amendment, 80 Miss. L. J. 1289 (2011).
  • COMMENT, Robyn Burrows, Judicial Confusion and the Digital Drug Dog Sniff: Pragmatic Solutions Permitting Warrantless Hashing of Known Illegal Files, 19 Geo. Mason L. Rev. 255 (2011).
  • COMMENT, Kristin M. Barone, Through The Looking Glass of the Fourth Amendment: The Unintended Consequences of Search Reform Leads to a Technological Erosion of Security in the Home, 13 Loy. J. Pub. Int. L. 159 (2011).
  • Abigail Brown, Something Smells Afoul: An Analysis of the End of a District Court Split, 36 Nova L. Rev. 201 (2011).
  • Orin Kerr, Applying the Fourth Amendment to the Internet: A General Approach, 62 Stanford Law Review 1005-1049 (2010).
  • Samantha Trepel, Digital Searches, General Warrants, and the Case for the Courts, 10 Yale J. L. & Tech. 120 (2007).
  • Richard P. Salgado, Fourth Amendment Search and the Power of the Hash, 119 Harv. L. Rev. F. 38 (2006).
  • Michael Bell, Caballes, Place, and Economic Rin-Tin-Tincentives the Effect of Canine Sniff Jurisprudence on the Demand for and Development of Search Technology, 72 Brook. L. Rev. 279 (2006).
  • Cecil J. Hunt II, Calling in the Dogs: Suspicionless Sniff Searches and Reasonable Expectations of Privacy, 56 Case W. Res. L. Rev. 285 (2005).
  • Orin S. Kerr, Searches and Seizures in a Digital World, 119 Harv. L. Rev. 531 (2005).
  • Orin S. Kerr, Digital Evidence and the New Criminal Procedure, 105 Colom. L. Rev. 279 (2005).
  • John M. Junker, The Structure of the Fourth Amendment: The Scope of Protection, 79 J. Crim. L. & Criminology 1105 (1989).
  • George Mohay et al., Computer and Intrusion Forensics (2003).
  • IIT Research Institute, Independent Review of the Carnivore System - Final Report (2000).

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