homicide vs sororicide

homicide

noun
  • A person who kills another. 

  • The department within a police force that investigates cases of homicide. 

  • The killing of one person by another, whether premeditated or unintentional. 

  • A victim of homicide; a person who has been unlawfully killed by someone else. 

sororicide

noun
  • A person who kills his or her sister. 

  • The killing of one's sister. 

How often have the words homicide and sororicide occurred in a corpus of books? (source: Google Ngram Viewer )