460 U.S. 276 (1983), 81-1802, United States v. Knotts

Docket Nº:No. 81-1802
Citation:460 U.S. 276, 103 S.Ct. 1081, 75 L.Ed.2d 55
Party Name:United States v. Knotts
Case Date:March 02, 1983
Court:United States Supreme Court

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460 U.S. 276 (1983)

103 S.Ct. 1081, 75 L.Ed.2d 55

United States



No. 81-1802

United States Supreme Court

March 2, 1983

Argued December 6, 1982




Having reason to believe that one Armstrong was purchasing chloroform to be used in the manufacture of illicit drugs, Minnesota law enforcement officers arranged with the seller to place a beeper (a radio transmitter) inside a chloroform container that was sold to Armstrong. Officers then followed the car in which the chloroform was placed, maintaining contact by using both visual surveillance and a monitor which received the beeper signals, and ultimately tracing the chloroform, by beeper monitoring alone, to respondent's secluded cabin in Wisconsin. Following three days of intermittent visual surveillance of the cabin, officers secured a search warrant and discovered the chloroform container, and a drug laboratory in the cabin, including chemicals and formulas for producing amphetamine. After his motion to suppress evidence based on the warrantless monitoring of the beeper was denied, respondent was convicted in Federal District Court for conspiring to manufacture controlled substances in violation of 21 U.S.C. § 846. The Court of Appeals reversed, holding that the monitoring of the beeper was prohibited by the Fourth Amendment.

Held: Monitoring the beeper signals did not invade any legitimate expectation of privacy on respondent's part, and thus there was neither a "search" nor a "seizure" within the contemplation of the Fourth Amendment. The beeper surveillance amounted principally to following an automobile on public streets and highways. A person traveling in an automobile on public thoroughfares has no reasonable expectation of privacy in his movements. While respondent had the traditional expectation of privacy within a dwelling place insofar as his cabin was concerned, such expectation of privacy would not have extended to the visual observation from public places of the automobile arriving on his premises after leaving a public highway, or [103 S.Ct. 1083] to movements of objects such as the chloroform container outside the cabin. The fact that the officers relied not only on visual surveillance, but also on the use of the beeper, does not alter the situation. Nothing in the Fourth Amendment prohibited the police from augmenting their sensory faculties with such enhancement as science and technology afforded them in this case. There is no indication that the beeper was used in any way to reveal information as to the movement of the chloroform container within the cabin, or in any

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way that would not have been visible to the naked eye from outside the cabin. Pp. 280-285.

662 F.2d 515, reversed.

REHNQUIST, J., delivered the opinion of the Court, in which BURGER, C.J., and WHITE, POWELL, and O'CONNOR, JJ., joined. BRENNAN, J., filed an opinion concurring in the judgment, in which MARSHALL, J., joined, post, p. 285. BLACKMUN, J., filed an opinion concurring in the judgment, in which BRENNAN, MARSHALL, and STEVENS, JJ., joined, post, p. 287. STEVENS, J., filed an opinion concurring in the judgment, in which BRENNAN, and MARSHALL, JJ., joined, post, p. 288.

REHNQUIST, J., lead opinion

JUSTICE REHNQUIST delivered the opinion of the Court.

A beeper is a radio transmitter, usually battery operated, which emits periodic signals that can be picked up by a radio receiver. In this case, a beeper was placed in a five-gallon drum containing chloroform purchased by one of respondent's codefendants. By monitoring the progress of a car carrying the chloroform, Minnesota law enforcement agents were able to trace the can of chloroform from its place of purchase in Minneapolis, Minn., to respondent's secluded cabin near Shell Lake, Wis. The issue presented by the case is whether such use of a beeper violated respondent's rights secured by the Fourth Amendment to the United States Constitution.


Respondent and two codefendants were charged in the United States District Court for the District of Minnesota with conspiracy to manufacture controlled substances, including but not limited to methamphetamine, in violation of 21 U.S.C. § 846. One of the codefendants, Darryl Petschen,

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was tried jointly with respondent; the other codefendant, Tristan Armstrong, pleaded guilty and testified for the Government at trial.

Suspicion attached to this trio when the 3M Co., which manufactures chemicals in St. Paul, notified a narcotics investigator for the Minnesota Bureau of Criminal Apprehension that Armstrong, a former 3M employee, had been stealing chemicals which could be used in manufacturing illicit drugs. Visual surveillance of Armstrong revealed that, after leaving the employ of 3M Co., he had been purchasing similar chemicals from the Hawkins Chemical Co. in Minneapolis. The Minnesota narcotics officers observed that, after Armstrong had made a purchase, he would deliver the chemicals to codefendant Petschen.

With the consent of the Hawkins Chemical Co., officers installed a beeper inside a five-gallon container of chloroform, one of the so-called "precursor" chemicals used to manufacture illicit drugs. Hawkins agreed that, when Armstrong next purchased chloroform, the chloroform would be placed in this particular container. When Armstrong made the purchase, officers followed the car in which the chloroform had been placed, maintaining contact by using both visual surveillance and a monitor which received the signals sent from the beeper.

Armstrong proceeded to Petschen's house, where the container was transferred to Petschen's automobile. Officers then followed that vehicle eastward towards the state line, across the St. Croix River, and into Wisconsin. During the latter part of this journey, Petschen began making evasive maneuvers, and the pursuing agents ended their visual surveillance. At about the same time, officers lost the signal from the beeper, but with the assistance of a monitoring device located in a helicopter the approximate location of the signal was picked up again about one hour later. The signal now was stationary, and the location identified was a cabin occupied by respondent near Shell Lake, Wis. The record before us does not reveal that the beeper [103 S.Ct. 1084] was used after the

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location in the area of the cabin had been initially determined. Relying on the location of the chloroform derived through the use of...

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