J. D. Robb 
Payback in Death: An Eve Dallas thriller (In Death 57) [EPUB ebook] 

Lt. Eve Dallas is back and this time she’s investigating the death of one of her own When a retired police officer is found dead in his home, Lt. Eve Dallas and the team are called to the scene to investigate. The victim is Martin Greenleaf, former Captain of Internal Affairs. At first glance it looks like suicide but Eve thinks there could be more to this carefully laid scene than meets the eye.Captain Greenleaf put a lot of cops away during his forty-seven years in Internal Affairs. Did the weight of the job finally prove too much for him? Or could this be a case of payback in death…..