Whitehead's name, and involvement in Houdini's death, remained practically unknown for many years afterwards – even Kenneth Silverman, author of the leading Houdini biography, gets the name of the assailant wrong. We owe our current knowledge of it to Don Bell, a Canadian antiquarian books dealer, who researched the case over 20 years. Bell's The Man Who Killed Houdini was published posthumously by a small Quebec press in 2004.

Whitehead, who – although he really was the divinity student he is always described as – was actually 31 years old at the time of the assault, lived on for almost 30 years. He adopted an extraordinarily low public profile and never gave a public statement about the incident; Bell says that he "was never heard from again" after Houdini's death, and lived for his last several decades as an outright recluse, living off "blood-red grapefruits and vegetables, and very little else." However, one of Bell's discoveries, which appears in his book, was the original affidavit given by him to the Commissioner of the Superior Court of Montreal in March 1927, five months after Houdini's death. This was tracked down, after significant effort, in the Detroit branch office of the company that had insured Houdini's life.

Bell cautions that this document "contains many discrepancies and lies." However, it is the only first-person account by Houdini's assailant, and as such is pertinent to your question. According to this document, Whitehead attended one of Houdini's lectures on 19 October 1926. The next afternoon he called on the entertainer at the theatre to request a private meeting, which was granted for 21 October. Sending his card up, Whitehead was admitted and introduced to two other McGill students who were also calling on Houdini. His account continues:

[10] The conversation ... turned to the question of keeping fit. Houdini remarked that he could duplicate a famous strongman's feat of supporting the pivot of a bridge over which was drive an automobile containing at least five people...

[12] Houdini suggested that I feel his abdomen – his muscles were like a washboard and his abdomen as unyielding as a sandbag. Houdini invited me to hit him...

[16] I struck Houdini quite moderately and he smiled and laughingly said, "Why/, hit me." [Sic – this is the original form in the deposition. Bell pointed out that "if one removes the slash and comma, one can assign a different meaning to the phrase: 'Why hit me?'"]

[17] I struck him a second blow slightly harder than the first – he gave not the slightest indication of any discomfort at either of the blows. Both blows were struck to the left side of his body and above the navel.

So Whitehead's version of events was that he struck Houdini with permission and fair warning, not very hard, on the opposite side of the body to the appendix whose rupture would eventually kill him.

This account was strongly contradicted by the other two McGill students, neither of whom knew the assailant and both of whom had been shocked by his actions. Their recollection was that Whitehead initiated the episode, asking "whether it was true that punches in the stomach did not hurt him. Houdini answered rather unenthusiastically that his stomach could resist much, although he did not speak of it in superlative terms." According to one of the students, Whitehead then struck Houdini without warning, and before he had the opportunity to tense himself. Both remembered "very heavy hammer-like blows" being struck "below the belt" by Whitehead.

However, Whitehead's exculpatory version continued:

[20] The conversation then went on in a general way for about an hour...

[22] I then left the dressing room and Houdini made some remark to the effect that he had enjoyed our conversation and asked me to call again whenever I liked.

[23] Houdini gave me the impression of being a very sick man, but his determination to keep going was equally apparent.

Moreover, Whitehead went on to claim that he had indeed called on Houdini on three further occasions, on 22 and (possibly) 23 October, and that "Houdini did not on any of these three occasions refer to the incident of my blows as having incommoded him in any respect, or caused him any harm."

Whitehead was never charged with any involvement with Houdini's death. There seem to be two key reasons why this was so that go beyond this effective denial of responsibility. One was that the death was written off at once as "accidental". The second is that it remains unclear whether the blows that Whitehead delivered led directly to Houdini's death from appendicitis – there is a small medical literature suggesting that blows to the stomach can lead to death in this way, but it is scarcely commonplace, and an alternative suggestion has always been that discomfort from the blows led the magician to ignore early warning signs of a quite separate problem with his appendix. We might, perhaps, add a third reason: that Houdini expired in an entirely different jurisdiction – he died in Detroit 10 days after his meeting with the Canadian, and hence the Montreal police never actually seem to have begun an investigation into the attack.

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