"He was fully eight feet from the casement, so that the assassin could not have reached in and struck him.There were no footprints by the window, as the assassin had strapped small boards upon his feet.It is most likely, therefore, that he has some peculiarity about his feet which he thought best to conceal.He is about five feet five inches tall, weighs about one hundred and thirty-five pounds, and steps three or four inches longer when the right foot is thrown forward than he does when the left foot leads.We have a cast of the assassin's hand showing unmistakable evidence of the habit of biting the nails, with the exception of that of thelittle finger, which nail, by the way, is abnormally long, and could only have been spared for some special reason.The murderer is most likely a foreigner.His handwriting would indicate this even if we did not know, from the books he read, how conversant he is with at least one foreign tongue.Again, he has some decided interest in the subject of cancers and, perhaps, some interest in legerdemain, if we may judge from his perusal of Robert Houdin's book.
"There are one or two other things I have learned, but this, so far as any present effect is concerned, is about all we know, and it doesn't seem to make the conduct of our search a very easy matter.We have clearly to deal with a man who is possessed not merely of low criminal cunning, but, I have reason to believe, with one who has education and culture, and, if anything can be judged from handwriting, rare strength of character as well.If we could only find some motive! No one but a maniac would do such a deed without a motive, yet we can't find one.A maniac! By Jove! I hadn't thought of that.What do you think of the idea? 'Though this be madness, yet there is method in't,' eh?"I told him that the maniac theory did not appeal to me very strongly."Madness, to be sure, is often exceedingly cunning," I said, "but it is hardly capable of such sustained masterfulness as our criminal has evinced.""Look here, Doc," Maitland said, breaking out suddenly, "I've an idea.Might not this fellow's interest in cancers be due to his having one himself? Suppose you make a canvass of the specialists on cancer in Boston and vicinity, and see if any of them remember being consulted by a patient answering the description with which I will provide you.In addition to this I will insert an ad in the papers calling attention to a new method for the cure of cancer, and asking all interested to call at your office for further particulars.The plan does not promise much, still it may bring him.What do you say?"I expressed my willingness to do all in my power to aid him, and he left me.The next morning's papers contained the advertisement and I had several calls in answer to it.These would have caused me much inconvenience had I not explained the whole ruse in confidence to amedical friend who made a specialty of the treatment of cancers, and persuaded him to come to my office during the hours specified in the advertisement.When a patient would call I would satisfy myself that it was neither the person we were searching for, nor anyone sent by him to make inquiries, and then turn him over to my colleague, Dr.Rhodes.It would never have occurred to me to interest myself in any patient who did not answer the description given me by Maitland, had he not especially cautioned me in this regard.
"We have," he said, "to deal with a man possessed of ability of no common order.We have already seen that he never runs a risk, however slight, which he can avoid.It is more than likely, therefore, if our advertisement meets his eye and interests him, he will inquire into it through some second party.Again, we are by no means certain that his interest in cancers is a purely personal one.Perhaps it is a wife, a sister, or some other relative who is afflicted.In this case we could hardly expect him to come himself.Let me caution you, therefore, to closely scrutinise all applicants and question them until you are satisfied they are in nowise connected with the man for whom we are searching."I followed this advice most carefully and had no difficulty in convincing myself that none of my callers had any relation whatsoever with the murderer of John Darrow.This order of things was continued for several days with the same result.In the meantime Maitland was working upon a new clue he had discovered.He would tell me all about it, he said, when he had followed it to the end.This was on Tuesday.On Friday he came to the house and informed us that he had met a man who had known a M.Henri Cazot, a Frenchman whose description seemed to tally perfectly with nearly all we knew of Mr.Darrow's murderer.