Also known as: protect people not places · Fourth Amendment protects people not places · Katz principle · reasonable expectation of privacy
Written by attorneys — see sources below.
A foundational principle of Fourth Amendment jurisprudence holding that constitutional protection extends to individuals' reasonable expectations of privacy rather than to particular physical locations. A search occurs when government conduct violates a person's subjective expectation of privacy that society recognizes as reasonable. What a person knowingly exposes to the public lacks protection even if the exposure occurs inside a home or office.
Patrick Phan places several opaque bags of household refuse at the edge of his driveway for scheduled pickup. Officers collect the bags without a warrant and discover evidence of illegal activity inside. Because Phan left the bags in an area accessible to the public, he held no reasonable expectation of privacy in their contents under the principle.
Pierre Poulin's wireless carrier releases four months of his historical cell-site location information to investigators pursuant to a court order lacking probable cause. The records reveal repeated visits to a private location. Under the principle, Poulin retains a reasonable expectation of privacy in the pervasive, long-term location data even though the carrier holds the records.
Pedro Pacheco stays overnight as a guest in Paula Pierce's home. Officers enter the residence without a warrant and seize items belonging to Pacheco. Because Pacheco exhibited a subjective expectation of privacy in the home that society recognizes as reasonable, the principle affords him standing to challenge the search.
Portia Price enters a public telephone booth, closes the door, and speaks in a low voice during a call. Officers attach a listening device to the outside of the booth without a warrant. The principle establishes that Price's reasonable expectation of privacy in the conversation triggers Fourth Amendment protection even though the booth is located in a public area.
Perry Pratt, a public hospital patient, provides a urine sample under a policy requiring testing of all pregnant patients for cocaine. Hospital staff turn positive results over to law enforcement without warrants. The principle requires the court to examine whether Pratt held a reasonable expectation of privacy in the medical information rather than focusing solely on the hospital setting.
In the fall of 1988, staff members at the Medical University of South Carolina (MUSC), a state-operated public hospital in Charleston, became concerned about an apparent increase in cocaine use by patients receiving prenatal treatment. In response, as of April 1989, MUSC began ordering drug screens on urine samples from maternity patients suspected of using cocaine based on nine specific criteria such as no prenatal care, late prenatal care, abruptio placentae, and unexplained intrauterine growth retardation. Positive results initially led to referrals for counseling and treatment through the county substance abuse commission, yet the incidence of cocaine use among patients did not appear to change. After Nurse Shirley Brown heard a news report about police in Greenville arresting pregnant cocaine users on child abuse theories, she discussed the matter with MUSC general counsel Joseph C. Good, Jr., who contacted Solicitor Charles Condon to offer the hospital’s cooperation in prosecuting mothers whose newborns tested positive. Condon organized a task force that included representatives from MUSC, local police, the County Substance Abuse Commission, and the Department of Social Services; their work produced the 12-page Policy M-7 governing management of drug abuse during pregnancy. The policy required chain-of-custody procedures for samples, set forth education and referral steps, and incorporated the threat of law enforcement intervention, including immediate police notification and arrest for patients testing positive a second time or missing treatment appointments. Under the initial version of the policy, patients testing positive during labor were arrested without a treatment option, but a 1990 modification extended the opportunity to avoid arrest by consenting to substance abuse treatment and periodic testing. The policy prescribed precise criminal charges depending on gestational stage—simple possession if 27 weeks or less, possession and distribution to a person under 18 if 28 weeks or more, and unlawful neglect of a child upon delivery while testing positive—and directed police to interrogate arrestees to identify the drug supplier. Between 1989 and 1994, MUSC performed approximately 600 drug screens on pregnant women, yielding 27 positive results and 10 arrests. Petitioners are the ten women arrested after positive tests while receiving obstetrical care at MUSC. Four were arrested before the treatment option was available and the remainder after failing to comply with treatment or testing positive a second time. They brought this action under 42 U.S.C. § 1983 against MUSC, the City of Charleston, and the solicitor, alleging that the urine tests violated the Fourth Amendment. The District Court granted respondents summary judgment on the special needs issue, submitted the consent question to the jury, and entered judgment for respondents after the jury found consent. The Fourth Circuit affirmed on the special needs ground without reaching consent, and the Supreme Court granted certiorari.
Pioneer Energy drivers are stopped at a city-operated checkpoint where officers use drug-sniffing dogs on every vehicle without individualized suspicion. The company challenges the program as an unreasonable seizure. The principle directs analysis to whether the drivers maintained a reasonable expectation of privacy in their vehicles' contents during the brief, suspicionless encounter rather than treating the highway as an unprotected place.
In August 1998, the city of Indianapolis began operating vehicle checkpoints on its roads with the aim of interdicting unlawful drugs. Between August and November of that year, the city conducted six such roadblocks, stopping 1,161 vehicles and arresting 104 motorists, of whom 55 were arrested for drug-related crimes and 49 for unrelated offenses. At each checkpoint, officers stopped a predetermined number of vehicles, typically 10 to 15, asked the driver a few questions, examined the vehicle's interior, and walked a narcotics-detection dog around the exterior. If evidence of a drug violation was detected, officers could search the car without consent; otherwise, they provided the driver with a flyer explaining the program and allowed the driver to proceed. The stops generally lasted two to three minutes. Respondents James Edmond and Joell Palmer were each stopped at a narcotics checkpoint in late September 1998. They filed a lawsuit in the United States District Court for the Southern District of Indiana on behalf of themselves and a class of motorists, claiming the checkpoint program violated the Fourth Amendment. The District Court denied the motion for a preliminary injunction. The United States Court of Appeals for the Seventh Circuit reversed that decision. The Supreme Court granted certiorari to review the case.
No. The principle recognizes that a person may retain a reasonable expectation of privacy in information or items even when physically present in an area accessible to others, provided the person seeks to preserve that information as private.
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…(a) that an enclosed telephone booth is an area where, like a home and unlike a field, a person has a constitutionally protected reasonable expectation of privacy; (b) that electronic as well as physical intrusion into a place that is in this sense private may constitute a violation of the Fourth Amendment; and (c) that the invasion of a…
…this Term, for example, we held that while an aerial observation from a helicopter hovering at 400 feet does not violate any reasonable expectation of privacy
…meaningfully interferes with freedom of movement, and obtaining and examining evidence may be a search when it infringes a reasonable expectation of privacy
…proceedings, but on limited grounds and as to some causes of action only. First, the Court of Appeal held plaintiffs had no reasonable expectation of privacy
…of having strangers take it,” United States v. Reicherter , 647 F. 2d 397, 399 (CA3 1981), respondents could have had no reasonable expectation of privacy in the inculpatory items that they discarded. Furthermore, as we have held, the police cannot reasonably be expected to avert their eyes from evidence of criminal activity that could have…
A defendant must demonstrate a personal reasonable expectation of privacy in the place searched. An overnight guest typically satisfies this test, while a short-term visitor present only for a commercial transaction generally does not.
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No. Individuals retain a reasonable expectation of privacy in historical cell-site location records that reveal pervasive, long-term movements even though the records are stored by a service provider.
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Justice Harlan's two-part inquiry asks first whether the person exhibited an actual subjective expectation of privacy and second whether that expectation is one society is prepared to recognize as reasonable.
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No. A person who leaves opaque trash bags on a public street for pickup has no reasonable expectation of privacy in the contents because the bags are readily accessible to members of the public.
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