A computer system uses risk-based principles to identify customers who have conducted money laundering activities. A money laundering risk score is derived from transactional information, background information, and/or due diligence information for each customer of a group of customers. Customers with higher money laundering risks are identified and monitored more closely. The computer system also assists a user to identify at least one transaction that has caused the identified customer to have a money laundering risk score that is in the higher percentiles of the customers.