the necessi 04-05 (2d Cir.1990) (upholding admissibility of expert testimony concerning drug-related function of ledger, shoe boxes, and other items seized from defendant’s apartment and explaining narcotics dealers’ use of “beepers” to avoid detection), cert. denied, 499 U.S. 940, 111 S.Ct. 1397, 113 L.Ed.2d 453 (1991); United States v. Campino, 890 F.2d 588, 593 (2d Cir.1989) (upholding trial court’s ruling admitting expert testimony concerning drug dealers’ use of electronic surveillance equipment similar to that found at defendants’ apartment and testimony that seized notebooks contained records of amounts owed by customers for cocaine transactions), cert. denied, 494 U.S. 1068, 110 S.Ct. 1787, 108 L.Ed.2d 788 (1990); United States v. Tutino, 883 F.2d 1125, 1133-34 (2d Cir.1989) (<HOLDING>), cert. denied, 493 U.S. 1081, 110 S.Ct. 1139,
holding admissible testimony of jurors describing jury review of information not admitted into evidence holding admissible expert witness testimony generally describing heroindistribution methods and interpreting organizedcrime terminology heard on taperecordings introduced in evidence holding that admission of hearsay testimony was harmless where the jury heard admissible testimony from three other sources to the same effect holding future dangerousness expert testimony to be admissible holding that improper admission of expert testimony was harmless in light of otherwise overwhelming evidence and fact that testimony covering substantially the same area was introduced without challenge