If your husband committed check fraud, he could go to prison, but if the story is really the way you say it is you should be fine! What I don't get is where did the money go? You spent the whole 4,000 in one night? You said that the bank called the next day. If you cash a check with insufficient funds, then yes you are responsible for the amount.
Have you tried to contact this Mr. Gray? It could be a money laundering scheme or something and THEY should be the ones doing the time. You should turn over their information to the police.




