The Least of These (The Detective Abbey Rhodes Mysteries)

Nashville Homicide Detective Abbey Rhodes is caught between a high-profile murder and multiple disappearances in a homeless camp. When the Mayor discovers the victim is the stepson of Jonathan Lee Thomas, a wealthy investor in the city's East Bank Project, he forces Abbey to abandon all other cases. She faithfully follows orders until her a friend goes missing.
Each case triggers Abbey's PTSD, bringing the past and its secrets crashing down around her. She stretches herself to the limit as her investigation jeopardizes the safety of her closest friends, and she must face the guilt when one of them is shot. In the end she learns every life has value.