In the old-fashioned drawing-room murder mysteries, the villain usually eliminated his target in some Victorian manner - asphyxiation in bed with a pillow, drowning in a clawed-foot tub, stabbing in the back with a letter opener - and then skulked away, convinced he had committed the perfect crime. In the plot of these mysteries, the foil to the crime always proved to be the experienced detection of a meticulous sleuth. AgathaChristie would use the skills of Hercule Poirot or Miss Marple within the plot of her novels to detect the one flaw in the murderer's technique. Perhaps there was some painfully obvious motive held by one of the guests at the summer home. Perhaps the villain's mother embroidered the pillow used to asphyxiate the victim, or the letter opener was engraved with a unique identifying mark. Regardless of the simplicity or complexity of the villain's methods, he was always caught. In these novels, there was no such thing as the perfect crime.
Audrey J. Burges,
Patterson v. Commonwealth: An Illustration of the Legal Complexity of DNA Databases,
Rich. J.L. & Tech
Available at: https://scholarship.richmond.edu/jolt/vol9/iss2/6