Upon questioning Agatha Christie says, “Of course, the poison bottle is mine, I am using it in my next novel, but I never opened it.”
A chromatogragy test was performed on the letter, and the ink came from a brown calligraphy pen.
A brown calligraphy pen was found on Agatha Christie’s writing desk.
After examining the pen, two sets of fingerprints were found on it.
One print belonged to Agatha Christie, after all, it was her pen, and the other belonged to Edgar Allan Poe.