Does a separate trial need to be held for a group of defendants accused of involvement in a conspiracy to distribute heroin?

First, although the moving defendants' involvement in the conspiracy and other crimes charged is not alleged to be on a scale with the involvement charged to some of their co-defendants, the moving defendants are themselves charged with serious crimes, including conspiracy to distribute heroin. Further, although defendants' alleged role in the conspiracy "may have been smaller or less central than that of certain other coconspirators, [that] does not mandate a separate trial." [United States v.] Nersesian, 824 F.2d [1294, 1304 (2d Cir.1987), cert. denied, 484 U.S. 957, 958 [108 S.Ct. 355, 357, 98 L.Ed.2d 380, 382] (1987), 1061 [108 S.Ct. 1018, 98 L.Ed.2d 983] (1988) ]; United States v. Vega, 458 F.2d 1234, 1236 (2d Cir.1972), cert. denied, 410 U.S. 982 [93 S.Ct. 1506, 36 L.Ed.2d 177] (1973); United States v. Aloi, 511 F.2d 585, 598 (2d Cir.), cert. denied, 423 U.S. 1015 [96 S.Ct. 447, 46 L.Ed.2d 386] (1975) ("differences in degree of guilt and possibly degree of notoriety," do not necessitate a severance).