During further meetings with Don Alberto, Martelli learns that Don Alberto's mother has a young child, a six-year-old deaf and mute girl with an intellectual disability. Martelli becomes convinced that the little girl is a witness to the killings after seeing that she compulsively pulls the heads off her dolls as if imitating the strangulations. One doll's head, that of Donald Duck, is found near the latest crime scene.
During subsequent conferences with Don Alberto, Martelli discovers that Don Alberto's mother has a six-year-old child, a deaf and mute girl with an intellectual disability. Martelli becomes certain that the little girl is a witness to the murders after noticing she compulsively removes her dolls' heads as if mimicking the strangulations. A doll's head, belonging to Donald Duck, is discovered near the latest crime scene.