A Capacity Of Vice by Taylor Saint-Savage

A troubled man who can’t or won’t speak, reliving tiny slices of his past, one painful bite at a time, decides that the best way to “vent” is by becoming a vigilante... A female detective whose moral compass has compelled her to blow the whistle on corruption in her department, making her a pariah, becomes obsessed with a serial killer who has murdered her partner... And the madman himself, a nearly unstoppable physical brute, does constant battle with his disturbed mind, which leads him on a horrific killing spree through Chicago’s mean streets... The gritty mystery of the men’s past carefully unfolds as their destinies and the detective’s converge, culminating in a final resolution to the Windy City’s serial killer problem. “There is a capacity of virtue in us, and there is a capacity of vice to make your blood creep.” —Ralph Waldo Emerson