That was what he must endeavour to discover.
Dispassionately, inexorably, the case was stated by the prosecution, based, as nearly every murder charge must be, on circumstantial evidence.
There were the undisputed facts that the prisoner had followed and endeavoured to see Lady Rawson, with the intention of recovering the stolen papers which he believed to have been—and were now known to have been—in her possession; that he had been close at hand at the moment the murder must have been committed, though none of the people who were in and out of the shop at the time, and who had all been traced and summoned as witnesses, could swear to having seen him. There was the agreement of time and place; even allowing for the delay caused by the fog, there was ample time for him to reach the church, “late and agitated” as he undoubtedly was, after committing the crime.
Above all, there, on the table, was the possible—nay, almost certainly the actual—weapon employed; one of the two pocket knives found on the prisoner at the time of his arrest. It was a flat, tortoiseshell penknife, of which the larger blade, of finely tempered steel, keen as a razor, constituted, in the opinion of the surgical experts, precisely the sort of instrument with which the wound was inflicted. The other knife—a thick blunt blade—was out of the question, part of a “motorists’s compendium,” fitted with several other small tools, none of which could inflict just such a wound.
Sadler, the taxi-driver, who had a bandage round his head and still looked shaky as a result of his smash up, identified the prisoner as the gentleman he had driven from Grosvenor Gardens to Rivercourt Mansions, having already picked him out unhesitatingly from among a number of other men.
Sadler’s further story was perfectly straightforward.
Having deposited his fare, and finding himself so close to the house of his sweetheart, Jessie Jackson, he drove slowly across to the post office, saw, through the window, Jessie in the shop with her aunt, guessed that in a few minutes she would be going up to dinner, and they would have the chance of a few words together, so pulled up in a side street, just by the house door, and out of sight from the shop, and smoked a “gasper” while he waited.
Presently he got down, had another squint into the shop, saw Mrs. Cave was now alone, so sounded his horn, “in a sort of signal we have,” and Jessie immediately came down and let him in at the side door. How long he was up in the kitchen with her he couldn’t say—not exactly—till her aunt called her down.
Then he waited for another few minutes, till he thought he heard someone “cranking up” his cab; ran downstairs, and sure enough the cab was disappearing down the street.
He went after it, and round the corner, just by the waterworks, found it standing, the engine still going, and saw a “nipper” running away.