In prosecution on drug distribution charge involving crack cocaine, Dist. Ct. did not commit plain error in admitting testimony regarding uncharged conduct concerning defendant's involvement in drug sales with third-party, even though defendant argued that said evidence merely showed his propensity to commit bad acts. Said evidence was admissible on issue as to whether defendant was aware of third-party’s drug activities, as well as whether defendant had access to crack cocaine to rebut defendant’s argument that he was unaware that clear package that he attributed to said third-party and delivered to informant contained crack cocaine. However, defendant was entitled to new sentencing hearing where: (1) at time of sentencing, Dist. Ct. did not apply Fair Sentencing Act (FSA), which reduced sentencing disparity between crack and powder cocaine; and (2) under Dorsey, 132 S.Ct. 2321, FSA’s statutory penalties applied to defendant’s sentence, even though defendant’s underlying conduct occurred prior to enactment of FSA.