In United States v. Poller, the Second Circuit (Parker, Bianco, Nardini) held that an officer’s use of an iPhone camera to view the contents of an automobile through tinted windows was not a search because the defendant did not have a reasonable expectation of privacy in the viewable contents of his car. The Court explained that any expectation of privacy in the contents of a car, even equipped with tinted windows, is not reasonable where state law requires window tints to remain somewhat transparent, and the defendant complied with that law. The tint did not prevent any passerby or police officer from seeing the interior of the car when parked on a public street. The Court also refused to apply the Supreme Court’s reasoning in Kyllo (which limited the use of thermal imaging by law enforcement) to the case because it did not involve privacy interests within the home.

The Second Circuit notably side-stepped the question about whether the officers’ physical touching of the exterior of the automobile constituted a “trespassory-search” under United States v. Jones. Instead, the Court explained that it did not need to reach the question because the defendant had admitted that there was no causal link between the alleged trespass and the discovery of the evidence. Indeed, the officers’ use of the iPhone cameras to observe the contraband without touching the car was sufficient to establish probable cause for the warrant to search the car.

This is a sharply-divided area of law and while the constitutionality of many possible fact scenarios remains unknown, Poller sheds some additional light on the lines that law enforcement is not permitted to cross in the course of investigation, and yet it leaves open two important questions, which we discuss below.

Background

In May 2022, during surveillance in preparation for the arrest of defendant Christopher Poller (“Poller”) as part of an investigation related to narcotics and weapons offenses, several Waterbury Police Department officers observed Poller park a gray Acura sedan on a public street near his residence. They witnessed individuals approach Poller in the car and exchange items with him, before Poller exited the car and went into his home. The officers believed, based on their training and experience, that these “exchanges” were consistent with hand-to-hand drug purchases.

Some of the officers approached Poller’s residence to execute a previously-obtained search warrant while another group approached the gray Acura sedan. The car had tinted windows, so one of the officers opened his iPhone’s camera and placed the phone against the window. The officer also held the camera near, but not touching, the window. Through the iPhone’s camera application, the officer believed he saw two firearms between the front seat and console. He walked around to the other side of the car, pointing on his phone to the two firearms to show his fellow officers. Another officer pulled out his iPhone and observed the two firearms through it. A third officer went to the front of the car, cupped his hands around his eyes, and announced that he observed a bag of heroin, two guns, and other contraband. This view was captured by his body camera, too.

The officers proceeded to tow the vehicle, obtained a warrant to search it, and then seized the guns and drugs they had observed. This evidence formed the basis of two charges against Poller: (1) one count of possession with intent to distribute fentanyl and cocaine base, in violation of 21 U.S.C. §§ 841(a)(1) and (b)(1)(C), and (2) one count of possession of a firearm in furtherance of a drug trafficking crime, in violation of 18 U.S.C. § 924(c)(1)(A)(i). Poller moved to suppress the evidence retrieved from his vehicle on the grounds that the officers’ observations through the iPhone camera violated the Fourth Amendment. The district court denied that motion.

Poller pleaded guilty to the charges pursuant to a conditional plea agreement that preserved his right to challenge the district court’s denial of the motion to suppress.

The Opinion

On appeal, the Second Circuit reviewed de novo the district court’s conclusion that: (1) the officers’ use of iPhone cameras did not violate Poller’s reasonable expectation of privacy because the technology is in general public use; and (2) it did not need to determine whether the officers’ physical touching of Poller’s vehicle was an unconstitutional “trespassory search” because that physical touching was not necessary for the officers to see the contraband. The Second Circuit affirmed the district court’s decision.

As the Poller Court observed, the Supreme Court has articulated two distinct tests for determining whether a police officer’s conduct constitutes a “search” for purposes of the Fourth Amendment, implicating a defendants’ right to be free from “unreasonable searches and seizures.” The first inquiry asks whether the officer violated a person’s reasonable expectation of privacy. The second inquiry asks whether the officer physically intruded on a constitutionally protected area. See United States v. Weaver, 9 F.4th 129, 141 (2d Cir. 2021). Poller argued that the evidence found in his vehicle must be suppressed under either inquiry: first, the use of the iPhone camera violated his reasonable expectation of privacy, and second, the officers’ physical touching of his vehicle while looking inside it was a physical intrusion on a constitutionally protected area.

The Court first addressed whether the officers’ use of their iPhone cameras to peer into the interior of the Acura sedan violated Poller’s reasonable expectation of privacy. Whether a defendant’s reasonable expectation of privacy has been violated involves a two-part inquiry: first, a court asks whether the defendant has “manifested a subjective expectation of privacy in the object of the challenged search,” and second, a court asks whether “society [is] willing to recognize that expectation as reasonable.” Under this standard, the Supreme Court has consistently held that “mere visual observation does not constitute a search” for purposes of the Fourth Amendment. United States v. Jones, 565 U.S. 400, 412 (2012). That is, there can be no reasonable expectation of privacy in something knowingly exposed to the public. This includes interior spaces visible to the public, such as items inside of a vehicle, but in plain view of someone on the outside. United States v. Dunn, 480 U.S. 294, 304 (1987).

Courts have applied this proposition even in cases where the interior of a car or other protected space is not visible to the naked eye, for example in cases requiring an officer to shine a flashlight into a vehicle to illuminate its contents, see Mollica v. Volker, 229 F.3d 366, 369 (2d Cir. 2000), or in cases where officers viewed a space using a “precision aerial mapping camera” from a high altitude, see Dow Chem. Co. v. United States, 476 U.S. 227, 229 (1986). In Poller, the Second Circuit concluded the officers’ observance of the contraband in Poller’s vehicle on a public street was on all fours with these precedents.

Poller argued that he was entitled to a reasonable expectation of privacy in his car because his tinted windows shielded the vehicle’s contents from passersby. The Court rejected this argument, explaining that the expectation of privacy does not turn on whether a space has been shielded from the gaze of a casual observer, but rather whether the interior of the vehicle may be “viewed from outside the vehicle either by inquisitive passersby or diligent police officers.” Texas v. Brown, 460 U.S. 730, 740 (1983). Additionally, state law required that the tinted windows permit a certain level of light to pass through. Poller had conceded that his windows permitted light to go through consistent with the law. Therefore, the Second Circuit concluded that Poller’s expectation that his tinted windows would shield the interior of his car from all observers was an unreasonable one.

Poller also argued that his reasonable expectation of privacy was nevertheless violated because the officers required the assistance of an iPhone camera to view the vehicle’s interior. He relied principally on the Supreme Court’s decision in Kyllo v. United States, where the Court held that “the use of a thermal-imaging device aimed at a private home from a public street to detect relative amounts of heat within the home” was a search, largely because a person’s privacy in his or her own home is the heart of the Fourth Amendment. 533 U.S. 27, 31 (2001). In rejecting Poller’s argument, the Second Circuit emphasized that the Kyllo Court explicitly excepted automobiles from its reasoning, and in subsequent decisions, neither the Supreme Court nor the Second Circuit has extended Kyllo’s reasoning beyond homes. The Second Circuit also concluded that an iPhone camera is not the equivalent of the “sense-enhancing technology” that the Supreme Court had been so wary of in Kyllo. In fact, an iPhone camera was more akin to “illumination devices” the Supreme Court has consistently sanctioned.

Therefore, the Second Circuit concluded that the officers’ use of the iPhone camera to peer into Poller’s vehicle while parked on a public street did not constitute a search under the Fourth Amendment.

The Court then turned to Poller’s argument that the officers’ physical touching of Poller’s vehicle while looking in its windows was a “trespassory search,” and therefore a separate violation of the Fourth Amendment. The Supreme Court has articulated that a trespassory search occurs when the government “physically occupie[s] private property for the purpose of obtaining information.” United States v. Jones, 565 U.S. 400, 404, 412 (2012). The panel observed that courts have been divided over the scope of this test. In a footnote, the panel compared decisions from other courts, including, for example, the Fifth and Sixth Circuits, which respectively concluded that “tapping tires” for an investigatory purpose, and “chalking a car tire,” constituted trespassory searches, while on the other hand, many district courts and state courts have concluded that “mere touching” of a vehicle or other item did not involve any intrusion onto private property.

The Second Circuit did not enter this debate. Instead, it concluded that, even assuming there was a trespassory search here, suppression of the evidence was not warranted because that trespassory-search would not have been the “but for” cause of locating the resulting evidence. This conclusion appears to have been easy to reach because Poller conceded that physically touching the car was not necessary for the officers to see the vehicle’s contents via their iPhone cameras. Therefore, the officers’ use of the iPhone without touching the car would have resulted—and in fact did result—in the constitutional seizure of the contraband, breaking the causal link required for suppression.

Discussion

The result of Poller’s appeal is perhaps not surprising, as courts in the Second Circuit have long permitted officers to view the interior contents of vehicles parked on a public street, even with tinted windows, using a flashlight. See United States v. Poller, 129 F.4th 169, 177 n.5 (2d Cir. 2025) (collecting cases). However, what is perhaps most interesting about this case is what was left unsaid. The Second Circuit explicitly left open two issues related to the scope of Supreme Court precedent about the Fourth Amendment.

First, as discussed, the Poller Court declined to consider whether officers’ physical touching of a publicly-parked vehicle might constitute a search. Therefore, the scope of a “trespassory search” remains an open question in the Second Circuit. Various factual scenarios—no matter how unlikely—could implicate this open question, including, for example, an officer’s use of chalk on a tire, climbing on a vehicle to better see its contents, or, as in Poller, leaning on a vehicle to look inside. In scenarios where the “physical touch” is “slight,” it seems likely a court will avoid the question and decide the issue based on causation, as the Poller Court did. The Court is right that whether the agents touched the car window or held their device a centimeter away made no difference on the facts presented here. However, a more significant intrusion is certainly fodder for a potential motion to suppress.  

Second, in a footnote, the Poller Court declined to adopt the district court’s analysis with respect to the scope of the Supreme Court’s Kyllo decision. See United States v. Poller, 129 F.4th 169, 180 n.6 (2d Cir. 2025). The district court had read Kyllo to suggest “that the use of technology is not a search when the technology is both widely available and routinely used by the general public.” United States v. Poller, 682 F. Supp. 3d 226, 231 (D. Conn. 2023) (quoting Naperville Smart Meter Awareness v. City of Naperville, 900 F.3d 521, 526 (7th Cir. 2018)). Based on this reading, the district court had concluded that, because an iPhone camera is in general public use, the use of it could not be a search under the Fourth Amendment. Id.

But the Second Circuit disclaimed this broad holding, instead explaining that the Kyllo Court had left open the possibility that the use of technology even in general use may be a search in certain circumstances. See Poller, 129 F.4th at 180 n.6. Moreover, the Court noted, a broad rule that the use of technology in general use is not a search would require complicated analysis with respect to the “proper contours” of such a rule. Id. Therefore, the Poller Court disclaimed any reliance on the fact that an iPhone camera may be in general use. It is not hard to imagine that the question of when a certain type of technology is in general use could itself become a difficult question for the court to answer, and one that might shed little light on the key question of whether law enforcement acted in a reasonable manner, consistent with the expectations of the public.

The Poller Court thus kept its holding limited to its specific facts and circumstances, leaving room for defendants to challenge officer conduct as constituting an unconstitutional search because of their use technology, even if that technology is in general use, or where they made physical contact with a defendant’s vehicle. Future cases will no doubt continue to explore these issues as new fact patterns, involving new forms of technology, are used by law enforcement in the future.