Brothers Till We Die (1978)

Vincenzo, a hunchback, plans a robbery of an armored police van with his gang. Once the job is pulled, his gang attempt to kill him and the band absconds with the loot. Vincenzo hides in the sewers before looking up his loony friend Monezza whom the police later interrogate for his involvement with vincenzo. Meanwhile, Vincenzo goes about getting revenge on his gang by knocking them off one at the time in various brutal fashion. imdb