From True Grit
As I understand it, Chaney... or Chelmsford, as he called himshelf in Texas... shot the senator's dog. When the senator remonstrated, Chelmsford shot him as well. You could argue that the shooting of the dog was merely an instance of malum prohibitum, but the shooting of a senator is indubitably an instance of malum in se.
Malum in se. The distinction is between an act that is wrong in itself, and an act that is wrong only according to our laws and mores. It is Latin.
I am struck that LaBoeuf is shot, trampled, and nearly severs his tongue, and not only does not cease to talk, but spills the banks of English!