Twain never said it. The quote is actually ‘I have never killed any one, but I have read some obituary notices with great satisfaction.’ It was written by Clarence Darrow, attorney in the Scopes monkey trials, in his autobiography ‘The Story of My Life.’
— Tweeting Twain Quotes That Never Were, regarding the recently popular pseudo-Twain quote “I’ve never wished a man dead, but I have read some obituaries with great pleasure.” (via nickdouglas)