atrocity vs unlawful act

atrocity

noun
  • An extremely cruel act; a horrid act of injustice. 

  • An object considered to be extremely unattractive or undesirable. 

  • The quality or state of being atrocious; enormous wickedness; extreme criminality or cruelty. 

unlawful act

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