Also known as: expectation of privacy test · reasonable expectation of privacy test · Katz test · reasonable expectation of privacy
Written by attorneys · grounded in primary & secondary sources — see below
A two-part inquiry used to determine whether government conduct constitutes a search under the Fourth Amendment. The inquiry first examines whether the individual exhibited an actual subjective expectation of privacy. It then asks whether that expectation is one society recognizes as reasonable.
Ethan Evans placed several sealed bags of household refuse at the edge of his driveway for scheduled pickup. Officers collected the bags without a warrant and examined their contents for evidence of illegal activity. The search yielded documents that the prosecution later sought to introduce at trial.
Emanuel Escobar's wireless carrier received a court order for four months of his historical cell-site location information. The records revealed repeated visits to a suspected accomplice's residence during the period of an ongoing fraud investigation. Prosecutors obtained the data without a warrant supported by probable cause.
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Elena Estrada stayed overnight at her cousin's apartment with the owner's permission. Officers entered the apartment without a warrant while she was asleep and seized personal items belonging to her. She later moved to suppress the evidence on Fourth Amendment grounds.
Ewan Eckhart entered a public telephone booth, closed the door, and placed a call. Officers attached a listening device to the outside of the booth and recorded the conversation without obtaining a warrant. The recording was offered against him at trial.
Eduardo Enriquez was present when officers arrived at a residence following a reported shooting. The officers remained on site for several days and conducted a thorough search of every room without a warrant. Items recovered during the extended search were later used to charge Enriquez.
Enzo Eastwood operated a vehicle repair shop subject to state licensing rules. Inspectors entered the premises during business hours and examined records and vehicles without obtaining a warrant or consent. Evidence of regulatory violations discovered during the inspection formed the basis for administrative penalties.
An overnight guest generally possesses a reasonable expectation of privacy in the host's home and may challenge a search of the premises. The expectation arises from the guest's permission to stay and the host's recognition of privacy in the shared space. Short-term commercial visitors lack this protection.
Individuals retain a reasonable expectation of privacy in historical cell-site location information held by third-party carriers. The government must obtain a warrant supported by probable cause to access pervasive long-term records. An administrative subpoena or court order under the Stored Communications Act is insufficient.
No reasonable expectation of privacy exists in garbage left for collection outside the curtilage of a home. Officers may search and seize such trash without a warrant or probable cause. The exposure to the public defeats any claim of privacy.
The defendant must first exhibit an actual subjective expectation of privacy in the place or item searched. Society must then recognize that expectation as objectively reasonable. Failure on either element means no Fourth Amendment search occurred.
…(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…