This book offers a conceptual model for understanding the nature of legal competencies. The model is interpreted to assist mental health professionals in designing and performing assessments for legal competencies defined in criminal and civil law, and to guide research that will improve the practice of evaluations for legal competencies. A special feature is the book's evaluative review of specialized forensic assessment instruments for each of several legal competencies. Three-fourths of the 37 instruments reviewed in this second edition are new.