The real art and science of the detective lies in building up one fact upon another until the edifice begins to assume intelligible shape. I am far from saying that a Sherlock Holmes is impossible. On the contrary, I have met people possessed as he was of a sense of intuition almost as keen and certain as seeing and hearing in ordinary men. But they are few. The average detective, though he may indulge in theories, depends really on facts and is wise not to wander very far from them. And he will find, if he is sufficiently practised and astute, that facts breed facts, and that a clue, even if it does not lead to the required solution, does often produce other clues that continue the chain unbroken. A “clue” that leads nowhere never was anything but a false clue from the beginning. And a detective is largely dependent upon what ordinary folk describe as luck or chance. His skill consists in making use of chance and in missing nothing that luck brings him.
The police have, in addition to the natural astuteness of individuals, the assistance of a singularly complete and effective organisation that enables them to push their inquiries far and wide and, when they have settled on their man, to weave round him a net from which escape is all but impossible. By telegraph and telephone, the police of the whole country can be put on the alert, descriptions can be circulated in a few minutes, information conveyed and facts gathered until the story is complete. The English police work under some difficulty since the methods of questioning and even bullying that are legal in France and are frequently permitted in America are rigidly forbidden here. English law really does try to live up to the theory that a man is innocent until he is proved guilty and that he must not be trapped into any unwary admission. I do not mean to say that the English police invariably abide by the strict letter of the law or always observe it in spirit. There are occasions when it is worth while to take risks. But, generally speaking, the law as it is and as it is administered aids the criminal and hampers the police, despite which, however, the latter are wonderfully successful.
Still, I can hear someone saying, many crimes go unpunished, many criminals remain undiscovered. True, but one has to remember that many criminals are known against whom there is no clear proof. The conviction of a wrong-doer is a matter of evidence not of belief. I am acquainted with two persons, one a man very well known in business circles, the other a lady of great charm and important position, who, I am quite sure, are murderers. The police are equally aware of the fact. But so skilfully have the criminals covered every trace that anything like proof would be wholly impossible.
And, again, it must not be forgotten that the criminal may be a person of first-class education, alert mentally, intrepid, with money, position and influence to aid him, and that he not only prepared the ground before the crime without hindrance or suspicion but was able to use his skill and resource in confusing the pursuit after it. A burglar, jewel thief, or the like, may be a person of the Bill Sikes variety, but he is quite as likely to be a University man with a profession and income and a wide circle of friends.
When brains are pitted against brains it is a straight fight and the best brains win quite irrespective of right or morality. The pursuit’s most valuable and useful asset lies in the fact that most criminals sooner or later make mistakes, and crime as a rule leaves no margin for error. The alert detective misses nothing of that sort and loses no opportunity his opponent may concede to him. But when all is said, facts remain the detective’s chief stock-in-trade, and it is the connected chain of established facts that eventually leads him to the solution required and the person wanted.
So far, for example, in this Clevedon case I had been groping in the dark, hanging grimly on to the few facts I had; and my blunderings and stumblings had led me to that little phial of poison in Nora Lepley’s secret hiding-place. I could not see yet the full bearing of that discovery, but it was a new fact which I had reached simply by following my nose.
Of course, I made a special journey into Midlington to look up Grainger, the chemist, who, I learnt, had been in business in the city about thirty-five years, was widely known, and very highly respected. I made a small purchase, and noticed that there were several bottles of Pemberton’s Drops in the large glass case that was full of various proprietary medicines.
“Is that stuff any use for sleeplessness?” I asked, pointing to one of the bottles.
“I don’t know,” he replied. “It seems fairly popular but I have never tried it.”
“Is it dangerous to take?”