Throughout this explanation Vance’s manner had been almost casual; yet the very serenity and assurance of his attitude conferred upon his words a curious sense of authority. Markham had listened with interest, though it could be seen that he did not regard Vance’s theorizing seriously.
“Your system ignores motive altogether,” he objected.
“Naturally,” Vance replied, “—since it’s an irrelevant factor in most crimes. Every one of us, my dear chap, has just as good a motive for killing at least a score of men, as the motives which actuate ninety-nine crimes out of a hundred. And, when anyone is murdered, there are dozens of innocent people who had just as strong a motive for doing it as had the actual murderer. Really, y’ know, the fact that a man has a motive is no evidence whatever that he’s guilty,—such motives are too universal a possession of the human race. Suspecting a man of murder because he has a motive is like suspecting a man of running away with another man’s wife because he has two legs. The reason that some people kill and others don’t, is a matter of temp’rament—of individual psychology. It all comes back to that. . . . And another thing: when a person does possess a real motive—something tremendous and overpowering—he’s pretty apt to keep it to himself, to hide it and guard it carefully—eh, what? He may even have disguised the motive through years of preparation; or the motive may have been born within five minutes of the crime through the unexpected discovery of facts a decade old. . . . So, d’ ye see, the absence of any apparent motive in a crime might be regarded as more incriminating than the presence of one.”
“You are going to have some difficulty in eliminating the idea of cui bono from the consideration of crime.”
“I dare say,” agreed Vance. “The idea of cui bono is just silly enough to be impregnable. And yet, many persons would be benefited by almost anyone’s death. Kill Sumner, and, on that theory, you could arrest the entire membership of the Authors’ League.”
“Opportunity, at any rate,” persisted Markham, “is an insuperable factor in crime,—and by opportunity, I mean that affinity of circumstances and conditions which make a particular crime possible, feasible and convenient for a particular person.”
“Another irrelevant factor,” asserted Vance. “Think of the opportunities we have every day to murder people we dislike! Only the other night I had ten insuff’rable bores to dinner in my apartment—a social devoir. But I refrained—with consid’rable effort, I admit—from putting arsenic in the Pontet Canet. The Borgias and I, y’ see, merely belong in different psychological categ’ries. On the other hand, had I been resolved to do murder, I would—like those resourceful cinquecento patricians—have created my own opportunity. . . . And there’s the rub:—one can either make an opportunity or disguise the fact that he had it, with false alibis and various other tricks. You remember the case of the murderer who called the police to break into his victim’s house before the latter had been killed, saying he suspected foul play, and who then preceded the policemen indoors and stabbed the man as they were trailing up the stairs.”[11]
“Well, what of actual proximity, or presence,—the proof of a person being on the scene of the crime at the time it was committed?”
“Again misleading,” Vance declared. “An innocent person’s presence is too often used as a shield by the real murderer who is actu’lly absent. A clever criminal can commit a crime from a distance through an agency that is present. Also, a clever criminal can arrange an alibi and then go to the scene of the crime disguised and unrecognized. There are far too many convincing ways of being present when one is believed to be absent—and vice versa. . . . But we can never part from our individualities and our natures. And that is why all crime inev’tably comes back to human psychology—the one fixed, undisguisable basis of deduction.”
“It’s a wonder to me,” said Markham, “in view of your theories, that you don’t advocate dismissing nine-tenths of the police force and installing a gross or two of those psychological machines so popular with the Sunday Supplement editor.”