Glenn has mentioned that he sees Claudius as being at least partially a sociopath. This lecture by Jeff Hancock, a professor of communication, delves into the linguistic variation between reports of murders given by imprisoned psychopaths versus imprisoned non-psychopaths.
Note his point that psychopaths tend to use murder to achieve an instrumental, material, goal. Also note the emphasis psychopaths put on eating and drinking when describing their murders.
"Hungry like the wolf: A word-pattern analysis of the language of psychopaths" Hancock, Woodworth & Porter. Legal and Criminological Psychology (2011)