Book excerpt: This new book written by ABA Commission on Mental and Physical Disability Law Director, John Parry, J.D. and forensic psychologist, Eric Y. Drogin, J.D., Ph.D., Manual has been formatted and written to guide lawyers, judges, law students, and forensic and other mental disability professionals through the maze of civil and criminal laws, standards, and evidentiary pitfalls, and forensic practices that characterize this area of the law. Moreover, it summarizes what empirical evidence exists to support or raise concerns about these legal standards and forensic practices when they are introduced in the courtroom.