There's something about novels that seems to provoke crime sprees in individuals. I heard once that the guy who shot Reagan and the guy who shot John Lennon both had gotten obsessed with The Catcher in the Rye. I also read that Rage was found in the backpacks of several school shooters, prompting Stephen King/Richard Bachman to pull it out of print. Now, we can add Agatha Christie to the fray.
No wonder my fifth grade English teacher looked at me askance when I did my book report on And Then There Were None . . .