"Since losing your key, how did you gain access to the office in the doctor's absence?"
"I have visited the office very seldom of late, and not once since losing the key, in the absence of Doctor Heath."
"Mr. Lamotte, was there any way to distinguish your lost key from that used by my client?"
"Yes; my key was newer than his, and brighter."
"It was my client's custom to keep an extra suit of clothes in his office closet, was it not?"
"Yes."
"And it would be very natural that, in exchanging one garment for another, a glove or handkerchief should be sometimes left in the discarded garment?"
"Quite natural."
"Now let us suppose that, on the night of the murder, my client, returning from a visit to Mapleton, where he was called to attend upon the wife of the murdered man, halted at his office, hung up his outer coat, and sat for a little time, writing or reading, or perhaps meditating.
"Let us suppose that on preparing to face the wind, that was rising rapidly, and blowing chill, he substituted a heavy overcoat for the one he had worn earlier in the evening; and that he discovered, when half way home, that he had left his much needed handkerchief with his discarded coat.