Whether the Fourth Amendment bars testimony by agents who contemporaneously overhear a defendant’s conversation through a transmitter worn by a consenting informant.
Holding
No, according to the four-Justice plurality. A defendant has no Fourth Amendment right to exclude a conversation that an informant voluntarily transmits to other agents, just as the defendant has no right to prevent the informant from recounting or recording the conversation.
Reasoning
Justice White’s plurality distinguished Katz. Katz involved the government’s secret electronic monitoring of a person’s telephone call without the participation or disclosure of anyone with whom the defendant was speaking. It did not establish a constitutionally protected expectation that a trusted conversational partner will neither reveal a conversation to police nor use equipment to preserve or transmit it.
Hoffa, Lewis, and Lopez established that a person assumes the risk that a confidant is a government agent, will later report the conversation, or will make an electronic recording of it. The plurality concluded that the same principle governs when the informant uses a transmitter that lets other agents hear the conversation at the same time. The defendant chose to speak to the informant and therefore assumed the risk that the informant would accurately disclose what was said.
The plurality rejected a constitutional distinction between an informant’s unaided recollection and electronic recording or transmission. If an informant may testify from memory without a warrant, the Fourth Amendment does not give the defendant a privilege to exclude a more accurate and reliable contemporaneous account created through a recorder or transmitter.
The later disappearance of the informant did not change the Fourth Amendment analysis. His absence might create ordinary evidentiary or prosecutorial-misconduct questions, but the constitutionality of the surveillance depends on what occurred when the conversations were monitored, not on whether the informant later became available to testify. Justice White’s view on this issue did not command a majority of the Court.