United States v. Concepcion Rubio, A/K/A "Carol Rubio," and Richard Rosado

PIERCE, Circuit Judge:

I. BACKGROUND

On June 5, 1981, Drug Enforcement Administration (DEA) informant Dennis Colla-zo twice telephoned Concepcion Rubio, a/k/a Carol Rubio, to arrange a meeting between her and Richard Rosado, prospective narcotics buyers, and DEA Special Agent Celerino Castillo, who was posing as a Mexican narcotics seller named “Fernando Cordoba.” Unknown to Rubio, the telephone calls originated from DEA headquarters and, with Collazo’s consent, were being tape-recorded by Special Agent Castillo. During the course of the telephone conversations, Collazo informed Rubio that “his…