Question: How does Richard find out what happened if Anthony was dead all along?
Answer: Because the gang did not expect Anthony to hang himself. They told him that he couldn't move from where they left him. I presume that the drunken/drugged up gang will have been laughing and telling everyone what they had just done to Anthony. Then later they would hear the tragic turn of events and try to keep it quiet. But it would be too late then and people would talk about their involvement.
Answer: Nanou 2 by Aphex Twin.