The charges are revolting.

Sodomy. Rape. Molestation. All of young boys. Over the span of a decade. By a respected -- celebrated -- Penn State University official.

Contained in a 23-page grand jury report , they tell the story of a famed athletic program with a dark, dark secret. They tell the story of a group of men who allegedly failed to act, putting the safety of children -- children they were purported to be helping -- on the line. They turned their heads, and the abuse continued.

Until now. Former assistant Penn State football coach Jerry Sandusky was arrested Saturday on a staggering 40 counts of sex crimes against minors. Some of these crimes were witnessed by Penn State students and employees as far back as 2002. Some of them were reported to high-ranking Penn State officials, including the school's famed football coach Joe Paterno and Athletic Director Tim Curley. And yet Sandusky's actions are only now coming to light.

See below a guide to the key players in the mind-boggling case -- and attempt to parse for yourself: Who knew what, and when? Who is culpable for this man's alleged abominable behavior? Who should be held responsible? Does the Penn State football program deserve to survive?