This document contains a final rule requiring banks and other depository institutions to report to the Department of the Treasury under the Bank Secrecy Act any suspicious transactions relevant to possible violations of federal law or regulation. The rule is adopted by the Financial Crimes Enforcement Network (``FinCEN'') to implement the authority granted to the Secretary of the Treasury by the Bank Secrecy Act. The rule is a key to the creation of a new method for the reporting by depository institutions, on a uniform ``Suspicious Activity Report,'' of suspicious transactions and known or suspected criminal violations; related rules have been or will be adopted by the five federal financial supervisory agencies that examine and regulate the safety and soundness of depository institutions.