"The deputy coroner said he found no trace of the poison on the knife blade." Miller paused to refill Mitchell's coffee cup. "Secondly, cyanide of potassium is not a drug which Miss Whitney would be apt to have around."
"I saw a half-filled bottle of it in Whitney's work-shop last Wednesday."
"Quite true, I saw it there myself," admitted Miller. "I also saw that
Whitney kept his studio workshop under lock and key."
"To outsiders; but it is just possible he is not so strict about the members of his household, his testimony to the contrary," argued Mitchell. "The point is not well taken, Captain, and even if it were," he stirred his coffee thoughtfully, "Miss Whitney did not need to enter her father's workshop to secure the cyanide of potassium; I find she buys all his photographic supplies at a shop not far from here, and recently purchased a new supply of cyanide."
"Purely circumstantial evidence," responded Miller, keeping his expression unaltered by an effort. The detective's last statement had startled him. "In regard to the flower which Spencer held in his hand: you say it was probably broken from the bouquet which she wore at the time of committing the crime—I am, for the sake of argument only, admitting that she might be guilty. The medical evidence went to prove that Spencer was killed between three and four in the morning; it is straining probabilities to claim that a young girl, in donning her wrapper, pinned on a bouquet of flowers."
"How do you know she was not fully dressed? It was not so late in the morning; she could have gone to bed after the crime, or she may not have gone to bed at all."
"All supposition," scoffed Miller.
"Not quite all." The detective, nettled by his jeering smile, spoke hastily. "On further inquiry I learned from one of the servants today that Miss Whitney had on the same dress Wednesday morning, when her screams aroused the household, which she wore at dinner the night before."
"Ah, indeed?" Miller's smile had ceased to be skeptical, it was strained.
"And which servant imparted that information to you?"
"Henry, the chauffeur."