The Poisoner's Handbook: Murder and the Birth of Forensic Medicine in Jazz Age New York

by Deborah Blum

I see poisoners—so calculating, so cold-blooded—as most like the villains of our horror stories. They’re closer to that lurking monster in the closet than some drug-impaired crazy with a gun. I don’t mean to dismiss the latter—both can achieve the same awful results. But the scarier killer is the one who thoughtfully plans his murder ahead, tricks a friend, wife, lover into swallowing something that will dissolve tissue, blister skin, twist the muscles with convulsions, knows all that will happen and does it anyway.

Think of that in conjunction with Claudius in Hamlet.