In his fourth book in the series, author Gabriel Cohen brings back Jack Leightner, a fifteen-year veteran of the NYPD’s Brooklyn South Homicide Task Force. Jack is called in to investigate a homicide, an apparently random murder of one man by another in a small deli, although he is quickly preempted by an agent with Homeland Security, who tells him he is taking over Jack’s case. And what initially appeared to be “another rinky-dink slaying, like a thousand others,” very soon turns out to have far more sinister aspects.
The second story line has to do with an incident in the more distant past, 1965 to be exact, when Jack’s 13-year-old brother, two years his junior, was killed in a senseless street incident by a young black teen, two feet from where Jack was standing. Jack has been guilt-ridden over all of the intervening decades. As the book opens, Jack finds a stranger at his door, following the directives known to most readers as the Twelve-Step Program of Alcoholics Anonymous, who is there to follow the eponymous Ninth Step: to make amends, as he tells Jack that it was he who killed his brother. In the conversation that follows, he makes it clear that he was hired for the purpose by a white man, whose name he never knew.
The action takes place in 2005, and the events of September 2001 are still very much on the minds of all New Yorkers and those entrusted with their safety. Although warned off any further investigation into both the current and the incident of decades before, “ancient history” as he is told by all those he questions, he cannot be dissuaded and continues both inquiries, and the fast-paced, well-researched novel goes down unexpected paths
I have to add that as a life-long resident of New York, most of that time spent in the borough of Brooklyn, the book engaged me and resonated with me to perhaps a greater extent than others. But this book’s appeal is by no means confined to New Yorkers – its strength lies in the tale itself, the wonderful writing, and the universal need for forgiveness within all of us imperfect humans, all of whom make mistakes, and some of whom commit acts of heroism. Highly recommended.

I enjoyed your review as I enyed this book. I agree it is well written and has much to recommend it.
I have read and reviewed this book quite recently. (See http://www.chescopa.com/books/2010/10/28/the-ninth-step/ if you would like to read my review.)