“What would my position be if I let him slip away with all this evidence against him?” The burly, phlegmatic man was sorely troubled in his mind.
“Consider,” I said, “all the essential gaps in your case. On the morning of the crime he can surely prove an alibi. He had been with his scholars till the last moment, and within a few minutes of McPherson’s appearance he came upon us from behind. Then bear in mind the absolute impossibility that he could single-handed have inflicted this outrage upon a man quite as strong as himself. Finally, there is this question of the instrument with which these injuries were inflicted.”
“What could it be but a scourge or flexible whip of some sort?”
“Have you examined the marks?” I asked.
“I have seen them. So has the doctor.”
“But I have examined them very carefully with a lens. They have peculiarities.”
“What are they, Mr. Holmes?”
I stepped to my bureau and brought out an enlarged photograph. “This is my method in such cases,” I explained.
“You certainly do things thoroughly, Mr. Holmes.”
“I should hardly be what I am if I did not. Now let us consider this weal which extends round the right shoulder. Do you observe nothing remarkable?”
“I can’t say I do.”