Through the Darkest Hour — Cassandra Giovanni

I was sent to save the city.
It turns out I'm the poison that will destroy it.
Sun City is a city divided, eaten away by the corruption of the Elite upper-class who reside in the Gold District. The drugs siphon down into the middle-class White District, killing the dreams of its residents until they end up in poverty-stricken Blue District.
Ana Jacobs has spent the last year of her life atoning for her father's sins and searching for the truth about the Trinity. During the day, she's Sun City's best cop. At night, she becomes Night Hawk, a bow and arrow wielding vigilante who dispatches those within the Trinity's corrupt Inner Circle. Between both worlds, she works to fight her demons.
Years of torture didn't break Ana, but the truth just might. Now, with the burden of how she's tied to the city's death sentence, a new villain places her and all she loves in their sights. She's determined to protect her newfound family, but when she comes face to face with the Nightwatchman, Ana realizes the man she loves is as tangled in the city's lies as she is.
Together, they might be able to save the city -- if only Ana lets Levi in.
But some demons never rest.