“I believe so. I am also an official consultant of both Scotland Yard and the Paris Sûreté.”
“Exactly. Is there any opportunity of error in identification by means of finger prints?”
“Granted a moderately clear impression and an able and honest expert to read it, there is not the remotest possibility of error.”
“The prints would be identical?”
“Oh, no; no two prints are ever identical. The pressure of the finger and the temperature of the body cause infinite minute variations.”
“But they do not interfere with identification?”
“No more than the fact that you raise or lower your voice alters the fact that it is your voice.”
“Precisely. Now, Dr. Barretti, I ask you to identify these two photographs and to tell us what they represent.”
Dr. Barretti took the two huge cardboard squares with their sinister black splotches and inspected them gravely. The jury, abruptly and violently agog with interest, hunched rapidly forward to the edges of their chairs.
From over Mr. Farr’s shoulder came an old, shaken voice—the voice of Dudley Lambert, empty of its erstwhile resonance as a pricked drum: “One moment—one moment! Do I understand that you are offering these in evidence?”