The King of Torts by John Grisham

The Office of the Public Defender is not known as a training ground for bright young litigators. Clay Carter has been there too long, and, like most of his colleagues, dreams of a better job in a real firm. When he reluctantly takes the case of a young man charged with a random street killing, he assumes it is just another of the many senseless murders that hit Washington D.C. every week.

As he digs into the background of his client, Clay stumbles upon a conspiracy too horrible to believe. He suddenly finds himself in the middle of a complex case against one of the largest pharmaceutical companies in the world, looking at the kind of enormous settlement that would totally change his life - that would make him, almost overnight, the legal profession's newest king of torts...