Dr. Nightingale: Races The Outlaw Colt was quick read. It is a series book in the A Deirdre Quinn Nightingale Mystery series.
The story starts out with a celebration of Wynton Chung's second year with the Hillsbrook Police Department ending in his death. Deirdre's police detective boyfriend, Allie Voegler, goes off the depth end on this case feeling his friend's death is his fault. His police captain, Joe Giugh, tells him to get out of town if he wants to keep his job after beating on lady during questioning. This situation has Deirdre hot on the case, but possible in over her head given that she is shot at.
I think I would call this a summer read. The plot was easy to follow, but the characters may be too thin for some readers.