True Blue by David Baldacci
As former D.C cop Mace Perry investigates a mysterious high-profile homicide in a last-ditch attempt to get her badge back, she finds herself on a collision course with the dark side of national security in this New York Times bestseller.
Mason "Mace" Perry was a firebrand cop on the D.C. police force until she was kidnapped and framed for a crime--and then spent two years in prison. Now she's back on the outside and focused on one mission: to be a cop once more. Her only shot to be a true blue again is to solve a major case on her own. But even with her police chief sister on her side, she'll have to work in the shadows: A vindictive U.S. attorney will do anything to send Mace back to jail. Enter Roy Kingman...
A young D.C. lawyer, Roy meets Mace after the murder of one of the firm's female partners. Soon Roy and Mace are investigating together--and uncovering surprising secrets from both the private and public world of the nation's capital.