Can defendants rely on the law of co-conspirator exception to the hearsay rule?

Defendants also rely on United States v. Mouzin (9th Cir.1986) 785 F.2d 682. In Mouzin, the court held that various ledgers which were introduced in a narcotics case were erroneously admitted under the co-conspirator exception to the hearsay rule. The court held an inadequate foundation had been laid for their admission. The court also refused to address the issue of a non-hearsay use for the ledgers, since this was never addressed in the lower court. Mouzin is thus distinguishable as it did not address the issue of a non-hearsay use of the ledgers.