I would look at the whole account and the history. Maybe the person wrote the check because they were expecting a large wire to be deposited into the account that day and it never came? I would check their average balances, transaction history, etc. I would see who the check was payable to, have they written checks to them before in large amounts, etc.
If the transaction doesn't fit, make sense, there have been no large deposits after that check bounced (that would justify them writing it, albeit a little too early), I would consider the SAR for check fraud. I am not sure if I would file one at that point, but it would probably go to my SAR committee for discussion/consideration...
CRCM + CAMS = certified compliance nerd
Opinions expressed in these threads are my own and not my employer's.