Santos, No. 060833 Conviction for murder while engaging in a drug offense is affirmed where: 1) because some drug conspiracies in violation of 21 U.S.C. section 846 are "punishable under" section 841(b)(1)(A), criminal liability under section 848(e)(1)(A) requires no active involvement in drug distribution; 2) the nexus between a murder and a drug offense need not be more than the "substantive connection" described in US v. [read post]