these things happened in the past

No they didn't. The cover-up of these events and the marginalization of the living relatives affected by them continues to the present day. People in the Church hierarchy are ACTIVELY doing this as part of their job and knowingly causing real suffering in the process.

The term in Anglo-American law is "accessory after the fact". It seems that Catholic canon law not only has no such concept, it says the secular authority should be prevented from applying it by every means possible.