Why was he never prosecuted? He had a trump card…

At the center of this story is a former, mid-century child actor. Several decades later, he was accused by three young male actors of molesting them in his capacity as mentor/coach. Why was he never prosecuted? He had a trump card: his own abuse, back then, by a major industry figure/founder. It was never a question of if, but how much, as far as this subsequent figure (at the time) was concerned.