In prosecution on drug distribution charge, Dist. Ct. did not err in admitting statements of confidential informant contained in audio-tape of conversation between defendant and confidential informant, even though confidential informant failed to testify at trial. No Sixth Amendment violation occurred, where instant statements were used to provide necessary context for defendant’s own admissions contained in audio-tape. Also, Dist. Ct. did not err in failing to give missing witness instruction relating to failure of confidential informant to testify, where defendant failed to show that confidential informant would have given helpful testimony.