In Dalia v. United States, the Supreme Court ruled that federal agents do not need to explicitly state their intent to execute a search warrant surreptitiously in order for it to be valid under the Fourth Amendment. The case arose when FBI agents obtained a warrant to search Bernard Dalia's office and home but did not inform him of their intention until after they had completed the covert operation. Upon discovering this, Dalia filed a motion arguing that his Fourth Amendment rights had been violated because he was not informed about the planned secret execution of the warrant beforehand. However, in an 8-1 decision, Justice William Rehnquist wrote on behalf of majority stating there is no constitutional requirement for law enforcement officers executing warrants to knock-and-announce themselves before entering premises or conducting searches.

In the dissenting opinion for Dalia v. United States, Justice Stewart argued that the Fourth Amendment does not permit a warrant authorizing officers to surreptitiously enter and install electronic surveillance equipment in private premises without explicit authorization from a judge. He contended that such an interpretation of the amendment would be contrary to its original intent and historical understanding. The majority's decision, he believed, gave law enforcement too much discretion in deciding how to execute search warrants which could potentially lead to abuses of power. Furthermore, he disagreed with their assertion that covert entries were necessary for effective law enforcement as there was no empirical evidence supporting this claim.