1. Marshal
1.1. Bacci
1.1.1. At the beginning Bacci didn't like Marshal because he thought he had deals with the Sicilian Mafia, so they didn't had the closest relationship, but at the end of the story, Marshal gave him an advice about what he could do with his future.
1.2. Cipolla
1.2.1. Marshal was kind and nice with him, despite he being the murderer of the Englishman, he was willing to help him.
2. Bacci
2.1. The Captain
2.1.1. Bacci saw The Captain as an example, he thought he was not only an excelent police, but a nice person. On the other hand, the Captain didn't like Bacci as much as Bacci liked him. He would've prefered to work with another person on the case rather than working with the city guy.
2.2. Miss White
2.2.1. It was difficult for them to comunicate, because Bacci didn't know a lot of English and wasn't easy for him to understand her. Meanwhile, Miss White didn't speak Italian, so she couldn't testify when Bacci first visited her.
2.3. Giovanna
2.3.1. Bacci wasn't a fan of Giovanna. He thought that because she's young, she is not a faithful witness and it wasn't a good idea to trust what she was saying.
3. Cipolla
3.1. Milena
3.1.1. Cipolla was madly in love with his wife. He always wanted the best for her. He tried be as supportive as he could, and strong for her while she was dying.
3.2. Langley-Smythe
3.2.1. They didn't had the best relationship. Langley has rude, disrespectful and cruel to both Cipolla and Milena. Finally at a moment of weakness, sadness and agriness Cipolla killed the Englishman