/REE-zuh-nuh-bul ek-SPEK-tuh-shun of PRY-vuh-see test/·doctrine
Also known as:reasonable expectation of privacy test · reasonable expectations of privacy test · Katz test
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 first part asks whether the individual exhibited an actual subjective expectation of privacy. The second part asks whether that expectation is one that society is prepared to recognize as reasonable.
Sources & Authorities· 1 primary source
Select any source to read its text and confirm it supports the definition.
Cases
Casebooks
How it applies
Common Examples
2
Directional Microphone Captures Calls
Ricardo Rojas stepped into a glass-walled smoking area on his company campus several times a day to make personal calls on his smartphone in a normal conversational tone without using speakerphone. Federal agents positioned on a public sidewalk used a high-powered directional microphone to record the content of those calls for a week. The recordings captured conversations that Rojas had taken steps to keep from public hearing. The agents' conduct invaded a reasonable expectation of privacy and therefore constituted a search.
Carrier Records Calls in Park
Roberto Reyes regularly stood in the same corner of a city park while making sensitive cellphone calls. At the request of federal agents, his carrier secretly reconfigured its network to capture and record all voice calls routed through the cell sector covering that corner. The recordings were later used against Reyes at trial. The network-level interception of call content invaded a reasonable expectation of privacy and therefore constituted a search.
United States v. Diggs385 F.Supp.3d 648
Common questions
Frequently Asked
5
Does the reasonable-expectation-of-privacy test require both a subjective and an objective showing?+
Yes. The first part of the test requires the individual to exhibit an actual subjective expectation of privacy by taking steps to keep information private. The second part requires that the expectation be one society is prepared to recognize as reasonable.
Supporting sources
Can a person have a reasonable expectation of privacy in conversations held in a semi-public space?+
Yes. A person who speaks in a normal tone without using speakerphone in a glass-walled smoking area exhibits a subjective expectation that the content of the calls will remain private. Society recognizes that expectation as reasonable when the government uses technology to capture conversations not knowingly exposed to the public.
Does the reasonable-expectation-of-privacy test protect the content of cellphone calls even when the caller stands in a public park?+
Yes. A caller who speaks into a phone exhibits a subjective expectation that only the other party will hear the words. Society treats the content of such calls as private when the speaker does not broadcast the words to bystanders, so government-directed network interception constitutes a search.
Supporting sources
What factors determine whether an expectation of privacy in a workplace on-call room is objectively reasonable?+
Courts examine whether the individual closed the door, spoke in lowered tones, used the room after hours, and whether the space had restricted badge access. Frequent invitations to third parties, leaving the door ajar, and the absence of locks or signs can defeat an objective expectation even in a secure wing.
Supporting sources
Does occasional invited use of a leased office without keys or a lease create standing under the reasonable-expectation-of-privacy test?+
No. A person who lacks any lease, keys, or formal right to exclude others and whose use depends entirely on the permission of the lessee does not possess a legitimate expectation of privacy that society recognizes as reasonable.
Supporting sources
Criminal Law & ProcedureConstitutional protection of accused persons · Arrest, search and seizureUBEFoundational