Walter Rane does a marvelous job depicting that horrible moment when The Lord comes to Cain (who has just slain his righteous brother, Abel) and asks, "Where is thy Brother?" Thus murder enters the world.
God finds Cain and Abel. Cain's thoughts and behavior is an Earthly duplication of the coding error expressed by Lucifer during the Angelic Wars. The error code of thought passed on from Lucifer and blossomed in Cain.