Partly depends on the agreement you had when he moved in. You can sue him for the damages if you want, but if he's in a bad situation, he probably won't have the money to pay you anything. No, there's no obvious criminal activity, so there's nothing for you to report to the police.
It's not your decision to "press charges." You might want to pull out your own lease agreement. Most landlords don't want you subletting like this without their approval.
You could have your own problems now if you push your luck. You can give him notice to move out. You can clean the place and tell him to pay for it.
If he doesn't, you can try taking him to small claims court, but again, he probably doesn't have the money to pay you anything.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.