Dalgliesh.

The Man Who Smiled begins with Wallander deep in a personal and professional crisis after killing a man in the line of duty; eventually, he vows to quit the Ystad police force for good. Just then, however, a friend who had asked Wallander to look into the death of his father winds up dead himself, shot three times. Ann-Britt Hoglund, the department’s first female detective, proves to be his best ally as he tries to pierce the smiling facade of his prime suspect, a powerful multinational business tycoon. But just as he comes close to uncovering the truth, the same shadowy threats responsible for the murders close in on Wallander himself.
All of Mankell’s talents as a master of the modern police procedural–which have earned him legions of fans worldwide–are showcased in The Man Who Smiled, which is the fourth of the eight Wallander books published thus far in English.