Overrated Genius Candidate #2.

Mark Twain/Samuel Clemens*. Notice that the big floppy mustache motif continues. One of the most read and respected American Writers of all time, famous even in his lifetime He was at times a cranky disorganized geezer, writer, and thinker. His editors should get half the credit. He wrote criticisms of contemporaries such as Jane Austen, James Fenimore Cooper, and George Eliot, for $ of course, in the "tooth and claw" style of literary criticism that he invented. He also invented the "Albert Einstein Look". 
*He is not known to have murdered anyone and he had many honorable qualities. He reportedly combed his hair with a spoon.