Breach of Duty by J. A. Jance

The Seattle that Beau knew as a young policeman is disappearing. The city is awash in the aromas emanating from a glut of coffee bars, the neighborhood outside his condo building has sprouted gallery upon gallery, and even his long cherished diner has evolved into a trendy eatery for local hipsters. But the glam is strictly surface, for the grit under the city's fingernails is caked with blood. Beau and his new partner Sue Danielson, a struggling single parent, are assigned the murder of an elderly woman torched to death in her bed. As their investigation proceeds, Beau and Sue become embroiled in a perilous series of events that will leave them and their case shattered -- and for Beau nothing will ever be the same again.