So I have this friend and he often has groups of friends that hang out at his house . So one time when he had a group of 8 people over his mom left her purse in the bathroom later when she found her purse in the bathroom she said the $60 in her purse was gone. So he knew that is was one of the 8 people he had over that took it.

He told me and one other person who was there since he trust us and knew it wasn’t us. So we came up with a plan to figure out who took the money. We invited all the same people over for a little get together and he purposely left his wallet in the bathroom. He left $40 in the wallet but marked both the $20s with a pen. Sure enough a couple hours later we checked and the $40 was gone. So we all went out to get food at a local restaurant while there we kept a eye on everyone’s money as they pulled it out to pay. And one of the guys pulls out a $20 with the mark. He confronted him about it and saw the other $20 in his wallet also had the mark so there was no doubt he stole the money. Also he most likely was the one who stole the $60 from his moms purse. The guy tried denying it but it was obvious and we had no doubt he stole it. What would you do in this situation?