The street lawyer / John Grisham.

A corporate lawyer in Washington goes to war against his own company to defend the homeless. It happens after Michael Brock is abducted by a homeless man and held hostage. The homeless man is killed by a police sharpshooter and the lawyer is rescued, but the experience changes his life. Michael was in a hurry. He was scrambling up the ladder at Drake & Sweeney, a giant D.C. law firm with eight hundred lawyers. The money was good and getting better; a partnership was three years away. He was a rising star with no time to waste, no time to stop, no time to toss a few coins into the cups of panhandlers. No time for a conscience. But a violent encounter with a homeless man stopped him cold. Michael survived; his assailant did not. Who was this man? Michael did some digging, and learned that he was a mentally ill veteran who'd been in and out of shelters for many years. Then Michael dug a little deeper, and found a dirty secret, and the secret involved Drake & Sweeney. The fast track derailed; the ladder collapsed. Michael bolted the firm and took a top-secret file with him. He landed in the streets, an advocate for the homeless, a street lawyer.