Reichs, Kathy. Temperance Brennan series.

Title from web page

It's never easy working fire scenes, Tempe thinks. Called to Washington, DC, to analyze the victims of a building set ablaze amid mysterious circumstances, she sees all her misgivings justified. The building site is in Foggy Bottom, a neighborhood with a colorful past and present, and the property's ownership becomes even more suspicious when Tempe delves into its past. The pieces start falling into place strangely and quickly, and, sensing a good story, Tempe teams with a new ally, telejournalist Ivy Doyle. Soon the duo learns that back in the thirties and forties the home was the hangout of a group of bootleggers and racketeers known as the Foggy Bottom Gang. Though interesting, this fact seems irrelevant-until the son of a Foggy Bottom gang member is shot dead at his farm in Fairfax County, Virginia. Coincidence? Targeted attacks? So many questions. As Tempe and Ivy dig deeper, an arrest is finally made. Then another Foggy Bottom Gang-linked property burns to the ground, claiming one more victim. Slowly, Tempe's instincts begin pointing to the obvious: somehow, her moves since coming to Washington have been anticipated in advance, and every path forward seems to bring with it a lethal threat

Read by Linda Emond