first-degree murder vs infanticide

first-degree murder

noun
  • An act that constitutes the crime of first-degree murder. 

  • The criminal offence of murder in a form considered by law to be the most serious; the precise distinction may vary by jurisdiction but typically involves premeditation, or the choice of victim or other circumstances being regarded as especially blameworthy. 

infanticide

noun
  • The murderer of a child: a person who has committed infanticide. 

  • The murder of an infant. 

  • The criminal offence of killing of a newborn, committed by its mother while psychologically disturbed by the effects of childbirth or lactation, not regarded as murder. 

  • The killing of a young, immature animal by a mature adult of the same species. 

  • The murder of a child by a parent; filicide. 

How often have the words first-degree murder and infanticide occurred in a corpus of books? (source: Google Ngram Viewer )