Board Thread:General Discussion/@comment-27079851-20161027130547/@comment-24674051-20161027165354

Exaclty (and love the Clue reference). The Evil Queen reveals that she is the one that murdered the Oracle to Archie, right before she kidnaps Archie. as for the poison, we don't know exactly how it was done, but the appearance matches what we have seen for Agrabahn viper poisoning (discounting what happened to Arthurs squire, that was another botched scene), so assuming that makes sense.

However, this does raise the question of who the Town Coroner is? (different topic needed for that discussion).