"Suppose we have a look at the other side of the building," replied the other.
Here the police had also done some going to and fro; the broad foot of Osborne was distinctly marked everywhere.
"And here is the sergeant's," said Ashton-Kirk, pointing. "The policeman's shoe is not to be mistaken, and Sergeant Nailor always wears soles that have been pegged."
Under one of the windows the investigator came to a halt. It was a window smaller than any of the others and much higher in the wall. Beneath it was a cellar opening with an iron grating.
"Look there," said the investigator, as he pointed to this latter.
Bat Scanlon looked, and saw a little ridge of mud upon one of the bars.
"From some one's foot," declared he. "It scraped off on the grating when they climbed up on it, maybe to reach the window."
Ashton-Kirk studied the particles clinging to the bar with much interest, an eager look in his eyes.
"It may be a coincidence," said he, "but I'm inclined to think not."
"What may be a coincidence?" asked Scanlon, as the other carefully scraped the particles from the grading into a compartment of a paper fold. But Ashton-Kirk made no reply except:
The big man obediently did so; on the ledge were the marks of fingers in the dust which damp had caused to stick there.
"And newly done," said Ashton-Kirk, as he dropped to the ground, a glint in his eye. "Very little dust has attached itself since they were made."
He began searching the surface of the ground under the window; finally he took a strong lens from his pocket and with increased interest resumed the inspection.
"Very likely one of the cops did this," said Scanlon. "Wanted to see if the window was fast."
Ashton-Kirk got up from his stooping position and slipped the lens back into his pocket.
"They would have tried the window from the inside in that case," said he. "It would have been easier to get at." He stood for a moment, reflecting; then he continued: "There seems to be very little more to be hoped for. Let us speak to Osborne before we go."
The big headquarters man was in the room across the hall from the one in which the crime had been committed.
"Well, all through?" he asked, genially, and with the manner of one whose position is assured.