The Philadelphia prosecutors are going after the Archdiocese of Philadelphian as an unindicted co-conspirator in the trial of Msgr. Lynn, and want to introduce evidence of the pattern of enabling abusers.
When I had lawyers review my book Sacrilege for libel issues, they were astonished at what bishops had done. Bishops came very close to being accessories before the facts to felonies. Bishops escaped because a prosecutor had to prove that a bishop assigned a known abuser to a parish with children with the intention of helping the crime be committed. Intention is very hard to prove, although when a bishop makes a known abuser a Boy Scout chaplain, circumstantial evidence is pretty strong.
Bishops repeatedly showed a total disregard for the safety of children, and as I understand it their legal culpability depends on the statues in each state about child endangerment. New Hampshire has a very strong statute; I do not know what Pennsylvania has. Lynn is no doubt guilty morally of endangering children, but whether his actions and failures are caught by the statute remains to be seen.