Grim and grisly, but not seeing the relationship to ‘gardening’, unless body parts were found in shallow, unmarked graves. These boys were most likely breaking and entering. A tragedy of their own making. The best thing this man can do now is to speak up and tell what happened. His life is already forever altered by this experience.
He used a rake, in an attempt to hide the evidence.
Like the unfortunate musician, bizarre gardening accident ;only different.