United States v. Alonzo, 991 F.2d 1422 (9th Cir. 1989)
United States v. Alonzo is a pivotal case in understanding the standards for establishing reasonable cause within the framework of federal criminal procedure.
Did the federal agents have sufficient reasonable cause to justify the issuance of a warrant based primarily on informants' uncorroborated testimony?
Reasonable cause, as required for the issuance of a warrant, must be based on practical, non-technical evidence considered in light of the totality of circumstances. Informant testimony can contribute to reasonable cause if sufficiently corroborated or inherently reliable.
The Ninth Circuit held that the warrant was valid, finding that the agents had established reasonable cause considering the corroborative efforts and reliability of the informants verified through additional surveillance activities.
The case is significant as it elucidates the reliance federal agents can place on informants' information while ensuring it stands up to judicial scrutiny. For law students, this decision illustrates the meticulous standards that must be met in probable cause determinations, emphasizing the need for law enforcement to not only gather information but also to substantiate it through strategic investigative measures.