Complex sentence: Humbert Nelli, a professor of history at the University of Kentucky, examines the Hennessy case in a chapter of "The Business of Crime" (1976), arguing that the murder was too poorly planned and amateurish to have been a Mafia hit.
Split into simpler sentences: Humbert Nelli, a professor of history at the University of Kentucky, examines the Hennessy case in a chapter of "The Business of Crime" (1976). Nelli argues that the murder was too poorly planned and amateurish to have been a Mafia hit.