This technical report describes the methodology of the Federal Justice Statistics Program (FJSP) dyad linking system. The FJSP dyad linking system provides a method of linking records across data sources and tracking person-cases through the stages of the federal criminal justice system. The report is designed for users of the FJSP dyad linking system as well as a more general audience interested in data linking methodologies. General background information about the Federal Justice Statistics Program is provided, along with a brief description of an earlier linking methodology. The dyad-based linking methodology is explained in detail, including descriptions of the datasets and variables used in each dyad, and the benefits of using this new approach are discussed. In-depth information about the implementation of the Jaro-Winkler matching algorithm is presented, as are detailed results by year for each dyad, and comparisons to the first generation linking system. Match rates and linking statistics for years 1994-2009 are included in tables and appendices for illustrative purposes.