Caution: Readers with non-European, non-Christian background might find the story too inaccessible. But that vanished for me after first couple of chapters that set the preamble; rest of the story should be reasonably accessible to all.
I'm a bit puzzled by its inclusion in Analog, that too when Campbell was the editor. It fits the pattern in that it's an intelligent reasonable story, but I haven't seen a lot of magic-wielding stories in these issues. Could this be of the type that alienated a lot of loyal Analog readers during the 1960s?
Story summary.Sir Pierre Morlaix, secretary to Count Edouard D'Evreux, found the Count murdered of a gunshot wound in his bed a certain morning. Investigator, Lord Darcy, with the help of Dr Pateley, physician, & Master Sean O Lochlainn, (licensed) Sorcerer! - will find the culprit. Sorcerer is the main forensics man!
Fact sheet.First published: Analog, January 1964.
Download full text from Project Gutenberg, Manybooks, Feedbooks, Webscription. [via Bill Garthright @ ClassicScienceFiction]
Among the stories from Astounding/Analog issues edited by John Campbell.
Related: Stories of Randall Garrett.