RICO stands for the Civil and Criminal "Racketeer Influenced & Corrupt Organizations" Act. The Act is codified at 18 U.S.C. §§1961-1968.
Most RICO-related cases are reported in the RICO Business Disputes Guide and/or the RICO Law Reporter. Also, Lexis has a RICO database (GENFED;RICO) that has cases, regulations and "applicable federal register materials."