CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE TENTH CIRCUIT.
White, J., delivered the opinion of the Court, in which Burger, C. J., and Blackmun and Powell, JJ., joined, in Parts I, II, and IV of which Rehnquist and O'connor, JJ., joined, and in Part III of which Brennan, Marshall, and Stevens, JJ., joined. O'connor, J., filed an opinion concurring in part and concurring in the judgment, in which Rehnquist, J., joined, post, p. 721. Stevens, J., filed an opinion concurring in part and dissenting in part, in which Brennan and Marshall, JJ., joined, post, p. 728.
JUSTICE WHITE delivered the opinion of the Court.
In United States v. Knotts, 460 U.S. 276 (1983), we held that the warrantless monitoring of an electronic tracking device ("beeper")*fn1 inside a container of chemicals did not violate the Fourth Amendment when it revealed no information that could not have been obtained through visual surveillance. In this case, we are called upon to address two questions left unresolved in Knotts : (1) whether installation of a beeper in a container of chemicals with the consent of the original owner constitutes a search or seizure within the meaning of the Fourth Amendment when the container is delivered to a buyer having no knowledge of the presence of the beeper, and (2) whether monitoring of a beeper falls within the ambit of the Fourth Amendment when it reveals information that could not have been obtained through visual surveillance.
In August 1980 Agent Rottinger of the Drug Enforcement Administration (DEA) learned that respondents James Karo, Richard Horton, and William Harley had ordered 50 gallons of ether from Government informant Carl Muehlenweg of Graphic Photo Design in Albuquerque, N. M. Muehlenweg told Rottinger that the ether was to be used to extract cocaine from clothing that had been imported into the United States. The Government obtained a court order authorizing the installation and monitoring of a beeper in one of the cans of ether. With Muehlenweg's consent, agents substituted their own can containing a beeper for one of the cans in the shipment and then had all 10 cans painted to give them a uniform appearance.
On September 20, 1980, agents saw Karo pick up the ether from Muehlenweg. They then followed Karo to his house using visual and beeper surveillance. At one point later that day, agents determined by using the beeper that the ether was still inside the house, but they later determined that it had been moved undetected to Horton's house, where they located it using the beeper. Agent Rottinger could smell the ether from the public sidewalk near Horton's residence. Two days later, agents discovered that the ether had once again been moved, and, using the beeper, they located it at the residence of Horton's father. The next day, the beeper was no longer transmitting from Horton's father's house, and agents traced the beeper to a commercial storage facility.
Because the beeper equipment was not sensitive enough to allow agents to learn precisely which locker the ether was in, agents obtained a subpoena for the records of the storage company and learned that locker 143 had been rented by Horton. Using the beeper, agents confirmed that the ether was indeed in one of the lockers in the row containing locker 143, and using their noses they detected the odor of ether emanating from locker 143. On October 8 agents obtained an order authorizing installation of an entry tone alarm into the door
jamb of the locker so they would be able to tell when the door was opened. While installing the alarm, agents observed that the cans containing ether were still inside. Agents ceased visual and beeper surveillance, relying instead on the entry tone alarm. However, on October 16 Horton retrieved the contents from the locker without sounding the alarm. Agents did not learn of the entry until the manager of the storage facility notified them that Horton had been there.
Using the beeper, agents traced the beeper can to another self-storage facility three days later. Agents detected the smell of ether coming from locker 15 and learned from the manager that Horton and Harley had rented that locker using an alias the same day that the ether had been removed from the first storage facility. The agents obtained an order authorizing the installation of an entry tone alarm in locker 15, but instead of installing that alarm, they obtained consent from the manager of the facility to install a closed-circuit video camera in a locker that had a view of locker 15. On February 6, 1981, agents observed, by means of the video camera, Gene Rhodes and an unidentified woman removing the cans from the locker and loading them onto the rear bed of Horton's pickup truck. Using both visual and beeper surveillance agents tracked the truck to Rhodes' residence where it was parked in the driveway. Agents then observed Rhodes and a woman bringing boxes and other items from inside the house and loading the items into the trunk of an automobile. Agents did not see any cans being transferred from the pickup.
At about 6 p. m. on February 6, the car and the pickup left the driveway and traveled along public highways to Taos. During the trip, the two vehicles were under both physical and electronic surveillance. When the vehicles arrived at a house in Taos rented by Horton, Harley, and Michael Steele, the agents did not maintain tight surveillance for fear of detection. When the vehicles left the Taos residence, agents
determined, using the beeper monitor, that the beeper can was still inside the house. Again on February 7, the beeper revealed that the ether can was still on the premises. At one point, agents noticed that the windows of the house were wide open on a cold windy day, leading them to suspect that the ether was being used. On February 8, the agents applied for and obtained a warrant to search the Taos residence based in part on information derived through use of the beeper. The warrant was executed on February 10, 1981, and Horton, Harley, Steele, and Evan Roth were arrested, and cocaine and laboratory equipment were seized.
Respondents Karo, Horton, Harley, Steele, and Roth were indicted for conspiring to possess cocaine with intent to distribute it and with the underlying offense. 21 U. S. C. §§ 841(a)(1) and 846. Respondent Rhodes was indicted only for conspiracy to possess. The District Court granted respondents' pretrial motion to suppress the evidence seized from the Taos residence on the grounds that the initial warrant to install the beeper was invalid and that the Taos seizure was the tainted fruit of an unauthorized installation and monitoring of that beeper. The United States appealed but did not challenge the invalidation of the initial warrant. The Court of Appeals affirmed, except with respect to Rhodes, holding that a warrant was required to install the beeper in one of the 10 cans of ether and to monitor it in private dwellings and storage lockers. 710 F.2d 1433 (CA10 1983). The warrant for the search in Taos and the resulting seizure were tainted by the prior illegal conduct of the Government. The evidence was therefore properly suppressed with respect to respondents Horton, Harley, Steele, and Roth, who were held to have protectible interests in the privacy of the Taos dwelling, and with respect to respondent Karo because the beeper had been installed without a warrant and had been monitored while its ether-can host was in his house.*fn2 We
granted the Government's petition for certiorari, 464 U.S. 1068 (1984), which raised the question whether a warrant was required to authorize either the installation of the beeper or its subsequent monitoring. We deal with each contention in turn.
Because the judgment below in favor of Karo rested in major part on the conclusion that the installation violated his Fourth Amendment rights and that any information obtained from monitoring the beeper was tainted by the initial illegality, we must deal with the legality of the warrantless installation. It is clear that the actual placement of the beeper into the can violated no one's Fourth Amendment rights. The can into which the beeper was placed belonged at the time to the DEA, and by no stretch of the imagination could it be said that respondents then had any legitimate expectation of privacy in it. The ether and the original 10 cans, on the other hand, belonged to, and were in the possession of, Muehlenweg, who had given his consent to any invasion of those items that occurred. Thus, even if there had been no substitution of cans and the agents had placed the beeper into one of the original 10 cans, Muehlenweg's consent was sufficient to validate the placement of the beeper in the can. See United States v. Matlock, 415 U.S. 164 (1974); Frazier v. Cupp, 394 U.S. 731 (1969).
The Court of Appeals acknowledged that before Karo took control of the ether "the DEA and Muehlenweg presumably could do with the can and ether whatever they liked without violating Karo's rights." 710 F.2d, at 1438. It did not hold that the actual placement of the beeper into the ether can violated the Fourth Amendment. Instead, it held that the violation occurred at the time the beeper-laden can was transferred to Karo. The court stated:
"All individuals have a legitimate expectation of privacy that objects coming into their rightful ownership do not have electronic devices attached to them, devices that would give law enforcement agents the opportunity to monitor the location of the objects at all times and in every place that the objects are taken, including inside private residences and other areas where the right to be free from warrantless governmental intrusion is unquestioned." Ibid.
Not surprisingly, the Court of Appeals did not describe the transfer as either a "search" or a "seizure," for plainly it is neither. A "search" occurs "when an expectation of privacy that society is prepared to consider reasonable is infringed." United States v. Jacobsen, 466 U.S. 109, 113 (1984). The mere transfer to Karo of a can containing an unmonitored beeper infringed no privacy interest. It conveyed no information that Karo wished to keep private, for it conveyed no information at all. To be sure, it created a potential for an invasion of privacy, but we have never held that potential, as opposed to actual, invasions of privacy constitute searches for purposes of the Fourth Amendment. A holding to that effect would mean that a policeman walking down the street carrying a parabolic microphone capable of picking up conversations in nearby homes would be engaging in a search even if the microphone were not turned on. It is the exploitation of technological advances that implicates the Fourth Amendment, not their mere existence.
We likewise do not believe that the transfer of the container constituted a seizure. A "seizure" of property occurs when "there is some meaningful interference with an individual's possessory interests in that property." Ibid. Although the can may have contained an unknown and unwanted foreign object, it cannot be said that anyone's possessory interest was interfered with in a meaningful way. At most, there was a technical trespass on the space occupied by the beeper. The existence of a physical trespass is only
marginally relevant to the question of whether the Fourth Amendment has been violated, however, for an actual trespass is neither necessary nor sufficient to establish a constitutional violation. Compare Katz v. United States, 389 U.S. 347 (1967) (no trespass, but Fourth Amendment violation), with Oliver v. United States, 466 U.S. 170 (1984) (trespass, but no Fourth Amendment violation). Of course, if the presence of a beeper in the can constituted a seizure merely because of its occupation of space, it would follow that the presence of any object, regardless of its nature, would violate the Fourth Amendment.
We conclude that no Fourth Amendment interest of Karo or of any other respondent was infringed by the installation of the beeper. Rather, any impairment of their privacy interests that may have occurred was occasioned by the monitoring of the beeper.*fn3
In United States v. Knotts, 460 U.S. 276 (1983), law enforcement officials, with the consent of the seller, installed a beeper in a 5-gallon can of chloroform and monitored the beeper after delivery of the can to the buyer in Minneapolis, Minn. Although there was partial visual surveillance as the automobile containing the can moved along the public highways, the beeper enabled the officers to locate the can in the area of a cabin near Shell Lake, Wis., and it was this information that provided the basis for the issuance of a search warrant. As the case came to us, the installation of the beeper was not challenged; only the monitoring was at issue. The Court held that since the movements of the automobile and the arrival of the can containing the beeper in the area of the
cabin could have been observed by the naked eye, no Fourth Amendment violation was committed by monitoring the beeper during the trip to the cabin. In Knotts, the record did not show that the beeper was monitored while the can containing it was inside the cabin, and we therefore had no occasion to consider whether a constitutional violation would have occurred had the fact been otherwise.
Here, there is no gainsaying that the beeper was used to locate the ether in a specific house in Taos, N. M., and that that information was in turn used to secure a warrant for the search of the house. The affidavit supporting the application for a search warrant recited that the ether arrived at the residence in a motor vehicle that later departed and that:
"For fear of detection, we did not maintain tight surveillance of the residence. . . . Using the 'beeper' locator, I positively determined that the 'beeper' can (5-gallon can of ether, described earlier in this affidavit) was now inside the above-described premises to be searched because the 'beeper' locator (direction finder) pinpointed the beeper signal as emanating from the above-described premises. . . . Again, later on Saturday (now in the daytime), 7 February 1981, my 'beeper' locator still shows a strong 'beeper' signal emanating from inside the above-described residence." App. 57-58.
This case thus presents the question whether the monitoring of a beeper in a private residence, a location not open to visual surveillance, violates the Fourth Amendment rights of those who have a justifiable interest in the privacy of the residence. Contrary to the submission of the United States, we think that it does.
At the risk of belaboring the obvious, private residences are places in which the individual normally expects privacy free of governmental intrusion not authorized by a warrant, and that expectation is plainly one that society is prepared to recognize as justifiable. Our cases have not deviated from this basic Fourth Amendment principle. Searches and
seizures inside a home without a warrant are presumptively unreasonable absent exigent circumstances. Welsh v. Wisconsin, 466 U.S. 740, 748-749 (1984); Steagald v. United States, 451 U.S. 204, 211-212 (1981); Payton v. New York, 445 U.S. 573, 586 (1980). In this case, had a DEA agent thought it useful to enter the Taos residence to verify that the ether was actually in the house and had he done so surreptitiously and without a warrant, there is little doubt that he would have engaged in an unreasonable search within the meaning of the Fourth Amendment. For purposes of the Amendment, the result is the same where, without a warrant, the Government surreptitiously employs an electronic device to obtain information that it could not have obtained by observation from outside the curtilage of the house. The beeper tells the agent that a particular article is actually located at a particular time in the private residence and is in the possession of the person or persons whose residence is being watched. Even if visual surveillance has revealed that the article to which the beeper is attached has entered the house, ...