At the City's Edge — Marcus Sakey

Jason Palmer loved being a soldier. But after returning home from Iraq with an "other than honorable" discharge, he's finding rebuilding his life the toughest battle yet.
Elena Cruz is a talented cop, the first woman to make Chicago's prestigious Gang Intelligence Unit. She's ready for anything the job can throw at her.
Until Jason's brother, a prominent community activist, is murdered in front of his own son.
Now, stalked by brutal men with a shadowy agenda, Jason and Elena must unravel a conspiracy stretching from the darkest alleys of the ghetto to the manicured lawns of the city's power brokers. In a world where corruption and violence are simply the cost of doing business, two damaged people are all that stand between an innocent child--and the killers who will stop at nothing to find him.