Shadow-Hawk: Protector of the Night - Angel Girl Trilogy, #2

The vigilante Shadow-Hawk is seen as an outlaw in the eyes of the public and the police. A young police detective named Kendall Vlad supports his crusade, but it wasn't enough to convince people that Solomon needs a protector like him. But when a notorious and deranged serial killer returns to the city after years of evading capture, Shadow-Hawk must prove himself to citizens that he is worthy of being a hero.