Earl Warren,
Lopez v. United States (373 U.S. 427…
“ They should not be defenseless against outright denials or claims of entrapment, claims which, if not open to conclusive refutation, will undermine the reputation of the individual agent for honesty and the public's confidence in his work. Where confronted with such a situation, it is only fair that an agent be permitted to support his credibility with a recording as Agent Davis did in this case. ”
