Did Aiwass really need to use a ritual to determine the suspect?
In fact, he did not.
When he heard Captain Camus suggest "copying a duplicate of the documents," he had actually already determined the suspect in his mind.
The logic was very simple.
Because the document that was handed over to Captain Camus was not the "top-secret diplomatic letter" whose content was unknown to everyone, but rather the "substantive evidence" whose content was already known—it was the letter that they had initially intercepted from a spy.
In other words, this was "the core evidence that locked down Miss Aleister's identity," and nearly everyone was aware of this fact.
Under the circumstances where Her Majesty the Queen had already warned that this matter should not be publicized any further, the Chief Secretary to the Minister of the Navy nevertheless requested Captain Camus to make a copy...
This, in itself, had already exposed the attitude of the Minister of the Navy.