The combination of Michael's betrayal and the chance at saving his own skin was enough to motivate Frankie to turn traitor.

Tom's line always struck me as funny. "They'd already had him on possession, bookmaking, murder 1, and a lot more."

Once you throw in Murder 1, what else do they really need? What could the "lot more" be?

Also, what does Tom mean by "possession?" Possession of drugs?

Was old-school Frankie really likely to be personally involved with drugs? He is unhappy with the Rosato's emphasis on the "junk dope." It seems unlikely he would "possess" drugs.