Walter Mosley’s saga of the post-Second World War history of Los Angeles, as seen through the eyes of the black community, has reached 1965. In Little Scarlet (Weidenfeld & Nicolson, £12.99, offer £10.39) the Watts district is quiet and tense after five days of race riots. Police and National Guardsmen are everywhere. The acrid smell of smoke lingers. Easy Rawlins, unofficial sleuth, wanders out to witness the devastation. A white cop approaches him. This time, unexpectedly, he’s not in trouble. A young black woman, Little Scarlet, has been strangled, and Rawlins is asked to hunt down her suspected killer — a white man last seen fleeing a violent mob.

The white LA police fear that their inquiries might trigger another riot; Rawlins, they feel, can move around freely. The absorbing mystery, as in all Mosley’s Easy Rawlins books, is accompanied by a perceptive, sometimes shocking, portrayal of the surrounding society and the racial politics of the troubled city. Little Scarlet is the ninth novel in the Rawlins series. The previous two were slight disappointments, but he’s back in terrific form.

The author of The Oxford Murders (Abacus, £9.99, offer £8.49), an Argentinian, is also a mathematician. It’s a tribute to Guillermo Martínez that he has managed to write an intellectual thriller that can be much enjoyed even by those — myself included — whose grasp of mathematics is limited. A young Argentinian student comes to Oxford to continue his studies, and soon stumbles on the body of his landlady. The only clue is a circle. Other apparently unrelated deaths occur, each with its own symbol. If the student and his mentor, a famous Oxford logician, can work out the meanings behind the symbols, the killer will be unmasked. They do so entertainingly, with the help of Wittgenstein and several famous theorems. Martínez’s somewhat quirky descriptions of Oxford add to the charm.

Vu cumprà is the Italian slang name for black African street vendors, usually illegal immigrants, who make their pathetic living out of selling dodgy wares to tourists. One of them is shot in the middle of Venice, in what appears to be a carefully planned execution. But why? Commissario Guido Brunetti — appearing in his fourteenth novel — investigates, in the growing realisation of his ignorance about the semi-clandestine society living on the edge of poverty in the midst of Venetian plenty. The more he delves, the more is exposed about the nature of Italian corruption, local and national. In Blood From a Stone (William Heinemann, £15.99, offer £12.79), Donna Leon has a wonderful feel for the hidden evils that lie below the façade of the magical city, and Brunetti, sturdy family man and cynic, is an endearing guide into the machinations of Italian society.

Peter Robinson’s Yorkshire-based Inspector Alan Banks has been around even longer than Brunetti — for 15 novels — and, like Donna Leon, Robinson has kept up an astonishingly high standard. Banks is not as eccentric or memorable as some fictional coppers, but his very ordinariness makes him all the more convincing. In Strange Affair (Macmillan, £17.99, offer £14.39) Banks comes to London in response to an urgent but mysterious message from his brother. At the same time, a young woman driving up to Yorkshire is shot dead. Inspector Banks’s address is found in the pocket of her jeans. Banks’s private search for his now disappeared brother runs parallel to the inquiries into possible motives for the murder. Gradually, links between them start to appear. Robinson’s (and Banks’s) quiet style has perhaps led to his being underrated; but make no mistake, he’s among the very best.

To buy at offer price call Books First (0870 1608080)

Explore Books

• Book Extracts

• Book Reviews

• Books Group

• Audio Books

Times Recommends

• The 100 Best Books of the Decade
• The Times picks the 50 best paperbacks of 2009
• The conversation: James Ellroy