"At the City's Edge" by Marcus Sakey offers a good read but disappoints.
Jason Palmer returns from Iraq. He didn't get the send off he wanted as his discharge was not honorable since he got one of his men killed and the officials said it was his fault.
Now he's jogging and approached by a car with some men in it who want to forcibly put him in the car to talk about what his brother is doing. However, Jason manages to disarm the leader, take his gun away and leave the people in the car wondering what they did wrong.
Jason's brother, Michael is a crusader. He owns a bar and wants to improve his neighborhood which is having trouble with gangs. His wife was killed by a 13 year old in a stolen car and he cares for his 8 year old son, Billy, by himself. When Jason asks him about what the people in the car may have wanted, he doesn't tell him anything but shortly thereafter, he's murdered and his bar burned down.
Little Billy saw the killers and now they want to kill him. They break into his home, where Jason now lives but Jason hears them and escapes. He meets Officer Elena Cruz, a street cop but well regarded and a member of the anti gang intelligence unit. She knew Michael and is trying to find answers about his death.
With Officer Cruz and Jason both looking for the same thing, they join forces. When they do, they are told certain things will happen and maybe they can get the answers but all is not what it seemed.
Who killed Michael? All they know is that someone is arming the gangs of the neighborhood and setting them against one another which results in more killing.
Sakey is a good writer. The characters have flaws but are believable and well developed. However, he breaks no new ground here and the urban gang conflict has been told a number of times and this seems more of the same.