What should the sister do whose husband - the Rafidhi - disappeared three months ago, and it is presumed he was killed, and she wishes to annul the marriage?

If a man is absent from his wife, there are two scenarios: First, his absence is not indefinite, and he can be contacted. In this case, his wife is not permitted to marry unless it becomes impossible for him to provide for her. If that occurs, she has the right to request an annulment from the judge. Second, he is missing, and all news of him is cut off. Scholars have differed regarding the permissibility of his wife marrying [another man]. The summary of Ibn Taymiyyah's view is that she should wait for four years, then observe the iddah (waiting period) of death, after which she is permitted to marry. The involvement of a ruler is not a prerequisite.