Homicide is justifiable when committed by any person in any of the following cases:
A. when committed in the necessary defense of his life, his family or his property, or in necessarily defending against any unlawful action directed against himself, his wife or family;
B. when committed in the lawful defense of himself or of another and when there is a reasonable ground to believe a design exists to commit a felony or to do some great personal injury against such person or another, and there is imminent danger that the design will be accomplished; or
C. when necessarily committed in attempting, by lawful ways and means, to apprehend any person for any felony committed in his presence, or in lawfully suppressing any riot, or in necessarily and lawfully keeping and preserving the peace.