Isaltino de Jesus is a kind of right-hand man… More than that, he really is Jaime Ramos's right-hand man. Born in a low-income neighbourhood in Porto, Massarelos, he's since moved to the suburbs, he migrated to the outskirts, to Valongo, and he keeps a terribly low profile, he's fiercely dedicated to his boss, who he feels he owes his whole life to: his promotions, his entry into the force. To be honest, Jaime Ramos takes some advantage of that. Though Isaltino is much younger than Jaime Ramos, somehow he's far more old-fashioned and conservative than Jaime Ramos himself, which his boss is grateful for, as that's very convenient. Isaltino answers the phones, he takes care of a lot of paperwork Jaime Ramos doesn't even want to think about. Isaltino alsos covers for him, he protects him like a father, like an old man, he often calls him 'old bugger,' in fact, he often thinks to himself and says "old bugger" throughout the stories. Jaime Ramos can seriously get on his nerves, but he always ends up forgiving his boss and making excuses for him, for the man he sees as a genius, the man he dedicates such an essential part of his life to.
For the longest time, you could say Jorge Alonso was Jaime Ramos's confidant. He owned a bar in the Foz district, an Irish pub. He was the one who taught Jaime Ramos how to appreciate Irish whisky, how to tell whiskies apart and taste the differences between them. He taught him how to drink beer too, how to tell beers apart and how to appreciate the finest brews. He taught him that, in life, fine whiskies and fine beers aren't just whiskies and beers. They're symbols, signs. They're metaphors for appetizing things. He's a very conservative man, much like most of the characters Jaime Ramos becomes close to and befriends, and he's promised that the detective will inherit all the bottles of a particular Irish whisky he owns.
José Corsário is a black cop from Cape Verde. He's mixed race. He's the son of a musician from the islands, who was ultimately just a tax collector in the city of Mindelo, on the Island of São Vicente – but he loved 'mornas,' he was a music aficionado. After the independence of Cape Verde, his parents decided to stay in Lisbon, instead of going back to the islands, but José Corsário has a special relationship with his homeland. Every single year, he spends some time in Cape Verde, a land he misses, though he's never really lived there. You could say that he's a permanent reminder of the colonial empire. He works with Jaime Ramos and he's married, or at least has a girlfriend called Fátima, an Angolan from Benguela. And that network of relationships is always present in all the books, all these stories about Jaime Ramos, who's also very protective of José Corsário, who's sort of a dark angel in his life.
Olívia is a recent addition to Jaime Ramos's supporting cast. She works in the force, she's a very special inspector, she has a son she sees less and less of, because she has no choice. He's growing up and she lives by herself. She has a girlfriend, a much younger woman. They speed around Porto on a motorbike. They're very close and care deeply for one other. She's also a character Jaime Ramos takes under his wing. She's been through a lot in life, she's worked as a park ranger, as an officer of the court, she had a variety of jobs before ending up in the police, and she's become an increasingly important and decisive character throughout these books.
Rosa is Jaime Ramos's eternal girlfriend. They met in the beginning of Death in the Stadium, which was published in 1991, but they never got married, they never crossed the threshold that is moving in together. They live in neighbouring apartments. He lives on the first floor, she lives on the third. They take care of each other, with deep mutual respect. Jaime Ramos is very careless about those things, and Rosa is very committed, but she also has a bit of a temper, she's prone to outburts. There's some tension, on occasion, when Rosa tries to put him on a diet Jaime Ramos feels it's impossible to stick to. At other times, she tries to set him straight and make him take a break from work, Jaime Ramos also tries to escape, but I think they care a lot about each other. Otherwise they wouldn't have made it through eight books, at least.