No Good Deeds by Laura Lippman
When the body of Federal Attorney Gregory Youssef is found dumped on the edge of Baltimore, every law-enforcement officer in the city is determined to catch his killer. But four months on, no one has been brought to justice and the department is under massive pressure to deliver a suspect. Meanwhile, Tess' boyfriend, Crow, runs into a homeless black teenager and insists on helping him. He brings Lloyd home for some food and a bed for the night. When Tess mentions the Gregory Youssef case in his presence, Lloyd freezes. That night, Lloyd sneaks out of the house and disappears. What could be the link between Youssef's death and the teenager? Tess tracks Lloyd down and convinces him to share what he knows - which she then passes on to the press on the condition that Lloyd's name isn't used. But they use Tess' name instead ...The police start to put the screws on Tess to reveal her source, but to give them Lloyd's name would be equivalent to a death sentence - snitches aren't tolerated on the streets of Baltimore. Meanwhile Lloyd suddenly shows up at Crow's door. Another black teenager has been shot and it quickly emerges that Lloyd was the intended target. Lloyd has nowhere to run to and he certainly can't go to the police. Before long the situation spins wildly out of control, leaving Tess to fear not only for Lloyd, but also for those closest to her.