The Red Thumb Mark

by R. Austin Freeman

"It is."

"Have you given any attention to the subject of finger-prints?"

"Yes. A great deal of attention."

"Be good enough to examine that paper" (here the usher handed to Thorndyke the memorandum slip). "Have you seen it before?"

"Yes. I saw it at Scotland Yard."

"Did you examine it thoroughly?"

"Very thoroughly. The police officials gave me every facility and, with their permission, I took several photographs of it."

"There is a mark on that paper resembling the print of a human thumb?"

"There is."

"You have heard two expert witnesses swear that that mark was made by the left thumb of the prisoner, Reuben Hornby?"