A computer system conducts transactional monitoring to detect different types of possible cases in order to prevent financial crimes and assist businesses to comply with different types of laws and regulations. The computer system derives a total risk score for each of a group of entities based on risk factors. Each of the risk factors is assigned a risk score. The computer system also detects an entity when the total risk score of the detected entity differs from a reference derived from total risk scores of the group of entities by a pre-determined margin. The computer system also assists a user to identify at least one transaction that has caused the detected entity to have a total risk score that differs from the reference derived from the total risk scores of the group of entities.