See Page 44 of
http://www.ffiec.gov/bsa_aml_infobase/documents/new_6_2006/SAR_Act_Rev_10.pdfFrom the FFIEC Manual:
The need for a review of customer activity or transactions does not necessarily indicate a need to file a SAR. The time period for filing a SAR starts when the organization, during its review or because of other factors, knows or has reason to suspect that the activity or transactions under review meet one or more of the definitions of suspicious activity.64
The phrase "initial detection" should not be interpreted as meaning the moment a transaction is highlighted for review. There are a variety of legitimate transactions that could raise a red flag simply because they are inconsistent with an accountholder’s normal account activity. For example, a real estate investment (purchase or sale), the receipt of an inheritance, or a gift, may cause an account to have a significant credit or debit that would be inconsistent with typical account activity. The bank’s automated account monitoring system or initial discovery of information, such as system-generated reports, may flag the transaction; however, this should not be considered initial detection of potential suspicious activity.