Ignorance triumphs over science....
Both these turncoat doctors are newcomers to the United States; voice analysis may be able to find a hint of an accent-- either Slavic or Latin-- and therefore who the Dr X is/was. It depends on how important that identity is.
Victor Crist, in his blabbering, concedes that he knows that this doctor is violating public standards. English hangmen were known, and were a respected member of the community, because capital punishment was accepted as a norm. The French headsman was a hereditary job for the last 200 years, and "Monsieur de Paris" was an honored member of society. Robert Elliott and Joe Freancel were both known to be executioner for 50 years in New York, although the last executioner's identity was a well kept secret. These two were electricians. Joe Byrd pulled the switch in Texas foe about 30 years and was known.
If this doctor feels that his work is honorable, he should not be ashamed of his work, and although he should not flaunt it, there would be no need to hide. What does any shrink have to say about this? It would be interesting to hear what they say about the motivation and potential conflict; several executioners have killed themselves in the not so distant past.