I have been in touch with Marc who is trying to fix his silly mistakes. He was not aware of the serious implications of check fraud and was new into this territory of scamming.
You're partially misjudging the situation. He has scammed more people than you think, and I know some of his aliases. He is not paying you back because realizing it was a "silly mistake", but because he's about to get caught and the rest of his life was about be fuked. Do you realize he has known the severity of this, yet continues to do it because he got away with it for a while?
He missed going to jail by a thread several weeks ago, which I was directly involved in. Let's just say he deposited the check in the wrong bank account at the wrong time.
PS - do not PM me for details. And Marc, there are more people that want your head than you think. There is a hefty bounty for you.