The absence of motive would have appeared to most persons a fatal objection to the theory of, what I may call, the prosecution.
Permit me to congratulate you on the consistency and tenacity with which you have pursued the actual, visible facts." He bowed stiffly to Thorndyke (who returned his bow with equal stiffness), lighted the fresh cigarette, and once more leaned back in his chair with the calm, attentive manner of a man who is listening to a lecture or a musical performance.
"The evidence, then, being insufficient to act upon," Thorndyke resumed, "there was nothing for it but to wait for some new facts.

Now, the study of a large series of carefully conducted murders brings into view an almost invariable phenomenon.

The cautious murderer, in his anxiety to make himself secure, does too much; and it is this excess of precaution that leads to detection.

It happens constantly; indeed, I may say that it always happens--in those murders that are detected; of those that are not we say nothing--and I had strong hopes that it would happen in this case.

And it did.
"At the very moment when my client's case seemed almost hopeless, some human remains were discovered at Sidcup.