The tragic arc of "Mamma Roma" is sealed when Ettore discovers his mother's true profession. His pimp, Carmine, returns to blackmail Mamma Roma, demanding money and forcing her back onto the streets by threatening to tell Ettore her secret. When Ettore eventually learns the truth, he is shattered. This revelation destroys his already fragile sense of identity and his relationship with his mother, pushing him completely into delinquency. He rejects the respectable job she blackmailed a restaurant owner to give him and commits a petty theft at a hospital.
Ettore is arrested while sick with a high fever. In prison, he is treated inhumanely, tied to a wooden bed in a restraint cell. It is here that he dies, calling out for his mother. Pasolini films his death as a secular crucifixion, a direct visual homage to Andrea Mantegna's "The Lamentation over the Dead Christ." This elevates Ettore from a simple delinquent to a martyr, a Christ-figure sacrificed by an uncaring modern society. When Mamma Roma learns of his death, she runs home in a state of primal grief and attempts to throw herself out of her apartment window but is held back by neighbors. The final shot is from her perspective, looking out at the dome of the church, a symbol of the salvation she could never attain. The ending reveals that her struggle was always doomed; the societal forces and the weight of her past were insurmountable, making her son's death the inevitable price of her attempt to defy her fate.