Generally in these instances, the business on the check is either fake or is a legitimte business that had its checks counterfeited. Your subject is the person who forged the check and mailed it to your customer, which you do not know. Depending on how far down the scam rabbit hole your customer went, you may have information on where they were supposed to wire the funds to complete the scam in which case you may have a subject from that information.
Ultimately your SAR investigation should determine whether you have adequate information to identify a subject.
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