People v. Butler: A Canine Sniff of a Person’s Body Is a De Bour Level-Four Search Requiring Probable Cause

1. Introduction

In People v Butler (2025 NY Slip Op 04052), the Appellate Division, Third Department confronted a narrow but consequential Fourth Amendment and New York search-and-seizure question: what level of suspicion is required for police to conduct a narcotics canine sniff of a person’s body during a traffic stop?

The case arose from a traffic stop in Broome County. After defendant Devon T. Butler exited his vehicle, an officer used a canine to sniff the vehicle and then sniffed Butler’s person. The dog allegedly placed its nose in Butler’s “groin/buttock region” and alerted. Butler fled; police later recovered a discarded package of heroin along his flight path. Butler moved to suppress the heroin and his statements, arguing the canine sniff and subsequent police conduct were unlawful.

The litigation has an unusual procedural posture: it returned to the Third Department after a prior Third Department decision and a Court of Appeals reversal and remittal. The key issue on this appeal was the correct legal standard (within New York’s De Bour framework) governing a canine sniff of a person’s body.

2. Summary of the Opinion

The Third Department held that a canine sniff of a person’s body is an especially intrusive search implicating heightened privacy and dignity interests, and therefore can be justified only at People v De Bour level four—i.e., upon probable cause to believe the target has committed a crime.

Because County Court evaluated the canine sniff under the lesser “reasonable suspicion” standard, the Third Department reversed and remitted for County Court to determine:

  • whether police had probable cause to conduct the canine sniff of Butler’s body;
  • if probable cause was lacking, whether Butler’s abandonment of heroin was sufficiently attenuated from the illegality; and
  • whether Butler’s statements were sufficiently attenuated from any unlawful police conduct.

The court expressly disavowed its prior holding in this very case that “reasonable suspicion” sufficed for a canine sniff of the body.

3. Analysis

3.1. Precedents Cited

The opinion is built around New York’s tiered street-encounter/search jurisprudence and prior canine-sniff decisions that placed different sniffs at different rungs of the De Bour ladder depending on intrusiveness and privacy expectations.

People v De Bour (40 NY2d 210 [1976])

People v De Bour supplies the controlling analytic framework: “graduated levels of suspicion corresponding with levels of permissible police intrusion,” requiring courts to weigh the governmental interest against the encroachment on privacy and personal security. The Third Department treated De Bour as the organizing principle and framed the ultimate question as where a canine sniff of a person’s body fits within that spectrum.

People v Dunn (77 NY2d 19 [1990], cert denied 501 US 1219 [1991])

People v Dunn is cited for two related propositions: (1) canine sniff searches can be analyzed under De Bour, and (2) a canine sniff of a vehicle’s exterior during a traffic stop requires only level-two founded suspicion. The Third Department used Dunn as a comparator: vehicle-exterior sniffs are less intrusive and involve a reduced expectation of privacy, helping explain why a lower threshold was accepted there.

People v Devone (15 NY3d 106 [2010])

People v Devone is cited to show that canine sniff searches in an apartment building’s common hallway demand a higher threshold—level-three reasonable suspicion. The Third Department emphasized that Devone explicitly considers both intrusiveness and privacy expectations, illustrating the adjustable nature of De Bour depending on setting.

People v Offen (78 NY2d 1089 [1991])

People v Offen is included among Court of Appeals decisions applying De Bour to canine sniff scenarios. Its presence reinforces the broader doctrinal point: New York treats canine-sniff legality as context-dependent under the graduated-suspicion model rather than as a single universal rule.

People v Davis (204 AD3d 1072 [3d Dept 2022], lv denied 38 NY3d 1032 [2022])

People v Davis is cited for the general De Bour balancing formulation—government interest versus the encroachment on individual privacy and security—supporting the Third Department’s methodological emphasis on intrusion and expectation of privacy as the key variables.

Prior iterations of this case: (196 AD3d 28 [3d Dept 2021], revd 41 NY3d 186 [2023]) and (41 NY3d 186 [2023])

The opinion’s most important “precedent” is the Court of Appeals’ earlier decision in this very prosecution.

  • In (196 AD3d 28 [3d Dept 2021]), the Third Department had held (a) a body sniff is a search, but (b) only reasonable suspicion was required, and it found that standard satisfied.
  • In (41 NY3d 186 [2023]), the Court of Appeals held definitively that a canine sniff of the body is a search under the Fourth Amendment and highlighted the “undignified and disconcerting” nature of an unfamiliar animal’s snout and jaws near vulnerable body parts, as well as the sanctity of bodily autonomy. However, it remitted under the “LaFontaine rule” because County Court had not made the necessary determinations on the governing standard and related issues.

The Third Department treated the Court of Appeals’ language on intrusion and bodily privacy—though delivered in the context of defining the conduct as a “search”—as strong guidance in placing the sniff at the top tier of De Bour.

People v LaFontaine (92 NY2d 470 [1998]) and CPL 470.35 (1)

These authorities explain the appellate constraint that shaped the procedural path: appellate courts generally should not decide issues not reached by the suppression court when fact-finding and initial legal determinations remain to be made. The Court of Appeals invoked this principle to remit; the Third Department then followed the remittal logic again, sending the matter back because County Court applied the wrong threshold.

People v Thomas (42 NY3d 236 [2024])

Cited to support remittal where the suppression court applied a lesser standard than what is ultimately required. The Third Department used People v Thomas to justify sending the case back for a probable-cause determination rather than deciding it in the first instance.

Katz v United States (389 US 347 [1967]) and Cicci v Chemung County (122 AD3d 1181 [3d Dept 2014], lv dismissed & denied 25 NY3d 1062 [2015])

Once the Third Department classified the body sniff as a probable-cause-level intrusion, it pointed to the familiar constitutional structure: probable cause typically triggers the need for a warrant unless an exception applies. Katz v United States provides the canonical articulation of the warrant requirement and exceptions. Cicci v Chemung County is cited for the same proposition in New York practice.

Attenuation/abandonment line: People v Wilkerson (64 NY2d 749 [1984]); People v White (153 AD3d 1369 [2d Dept 2017], lv denied 30 NY3d 1065 [2017]); People v Pirillo (78 AD3d 1424 [3d Dept 2010])

These cases guide the post-illegality analysis. If the canine sniff is unlawful, County Court must determine whether the heroin was abandoned in a way that is legally “spontaneous and precipitated by the illegality” (thus suppressible) or instead “a calculated act not provoked by the unlawful police activity” and therefore attenuated.

Attenuation of statements: People v Cook (206 AD3d 1236 [3d Dept 2022]) and People v Swain (168 AD3d 1130 [3d Dept 2019], lv denied 34 NY3d 938 [2019])

These cases frame the inquiry into whether subsequent statements are tainted by unlawful conduct or sufficiently attenuated to be admissible despite an initial constitutional violation.

3.2. Legal Reasoning

The court’s reasoning proceeds in three steps.

(1) Canine sniffs are not monolithic; De Bour requires context

Building on Court of Appeals authority, the Third Department reaffirmed that New York evaluates canine-sniff searches using the De Bour four-tier approach. The court treated the question as one of placement: at which tier does a body sniff belong?

(2) “Utility” and “discriminate nature” are constant; intrusion and privacy do the real work

The court acknowledged factors previously discussed by the Court of Appeals—dogs are useful, and they are “discriminate” in detecting only narcotics without revealing other private items. But the court reasoned those factors exist in every canine-sniff case and therefore cannot sensibly determine tier placement.

Instead, the court elevated the two variables that genuinely differ by setting:

  • Extent of intrusion (how physically, psychologically, and socially invasive the method is), and
  • Expectation of privacy (how strongly the law protects the space/interest intruded upon).

Using this lens, the court explained why a vehicle sniff (less intrusive, lower privacy expectation) can sit at level two (People v Dunn), why a hallway sniff sits higher at level three (People v Devone), and why a body sniff must sit higher still.

(3) A canine sniff of the body is uniquely invasive and implicates the highest privacy interest

The decisive move was to treat the body sniff as categorically different in kind from other canine sniffs. Relying heavily on the Court of Appeals’ description in (41 NY3d 186 [2023]), the Third Department emphasized:

  • the “objectively undignified and disconcerting” experience of a dog’s snout and jaws near (or in contact with) “vulnerable parts” of the human body; and
  • the paramount nature of the right to control one’s own person, “more sacred” and “more carefully guarded” than most others.

On that basis, the court held the intrusion on “personal privacy, security, and dignity” can be justified only at De Bour level four: probable cause. It expressly “disavow[ed]” its earlier ruling in this case applying the reasonable-suspicion standard.

Procedural consequence: remittal rather than final suppression ruling

Because County Court applied the wrong (lower) standard, the Third Department did not decide probable cause itself. Instead, it remitted for County Court to:

  • apply the probable-cause standard to the body-sniff decision;
  • if probable cause was lacking, determine whether abandonment and statements were attenuated from the illegality.

3.3. Impact

The opinion establishes a clear, high-threshold rule for New York practice (at least within the Third Department, and potentially persuasive statewide): police need probable cause before using a narcotics dog to sniff a person’s body during a traffic stop or similar encounter.

Likely practical consequences include:

  • Operational constraints on K-9 deployment: officers may continue to use dogs for vehicle-exterior sniffs under lower standards (per existing precedent), but must refrain from escalating to a body sniff absent probable cause.
  • Increased litigation on “probable cause” timing: future suppression hearings will focus on what officers knew before initiating the body sniff, and whether that information rose to probable cause.
  • Renewed focus on attenuation and abandonment: the opinion highlights that even if a body sniff is unlawful, admissibility may turn on whether flight/discarding contraband was provoked by the illegality (People v Wilkerson) and whether statements were tainted (People v Cook; People v Swain).
  • Doctrinal clarity within the De Bour framework: the decision signals that the most important determinants for canine-sniff tiering are not the dog’s accuracy or narrowness, but the human experience of the intrusion and the nature of the privacy interest at stake.

4. Complex Concepts Simplified

De Bour’s four levels (as used here)

  • Level 2 (“founded suspicion”): a moderate basis to suspect criminality; in canine-sniff caselaw, used for less intrusive contexts like a vehicle’s exterior (People v Dunn).
  • Level 3 (“reasonable suspicion”): stronger, articulable facts suggesting a person has committed/is committing a crime; used for more intrusive contexts like a building hallway sniff (People v Devone).
  • Level 4 (“probable cause”): facts and circumstances that would lead a reasonable person to believe a crime was committed and that the target is involved; the Third Department places a body sniff here.

“Search,” “probable cause,” and the warrant requirement

If police conduct is a “search,” it must be reasonable under the Fourth Amendment. A sufficiently intrusive search generally requires probable cause and—absent an exception—a warrant (Katz v United States).

“Abandonment” and “attenuation” after unlawful police conduct

Even if police conduct is illegal, evidence is not automatically suppressed if the connection between the illegality and the evidence is sufficiently broken. Under People v Wilkerson, the court asks whether the defendant’s act (like discarding drugs while fleeing) was prompted by the illegality (tainted) or was an independent, calculated act (attenuated).

5. Conclusion

People v Butler draws a firm constitutional line: because a canine sniff of a person’s body is uniquely intrusive and implicates the highest privacy and dignity interests, it belongs at the top of New York’s De Bour hierarchy and requires probable cause. The decision aligns doctrinal tiering with lived intrusiveness, rejects a one-size-fits-all view of canine sniffs, and sets up suppression litigation to focus on probable cause and, if needed, attenuation and abandonment under People v Wilkerson and related cases.