197.  Homicide is also justifiable when committed by any person in any of the following cases:
   1. When resisting any attempt to murder any person, or to commit a felony, or to do some great bodily injury upon any person; or,
   2. When committed in defense of habitation, property, or person, against one who manifestly intends or endeavors, by violence or surprise, to commit a felony, or against one who manifestly intends and endeavors, in a violent, riotous or tumultuous manner, to enter the habitation of another for the purpose of offering violence to any person therein; or,
   3. When committed in the lawful defense of such person, or of a wife or husband, parent, child, master, mistress, or servant of such person, when there is reasonable ground to apprehend a design to commit a felony or to do some great bodily injury, and imminent danger of such design being accomplished; but such person, or the person in whose behalf the defense was made, if he was the assailant or engaged in mutual combat, must really and in good faith have endeavored to decline any further struggle before the homicide was committed; or,
   4. When necessarily committed in attempting, by lawful ways and means, to apprehend any person for any felony committed, or in lawfully suppressing any riot, or in lawfully keeping and preserving the peace.
 

198.  A bare fear of the commission of any of the offenses mentioned in subdivisions 2 and 3 of Section 197, to prevent which homicide may be lawfully committed, is not sufficient to justify it.  But the circumstances must be sufficient to excite the fears of a reasonable person, and the party killing must have acted under the influence ofsuch fears alone.
 

198.5.  Any person using force intended or likely to cause death or great bodily injury within his or her residence shall be presumed to have held a reasonable fear of imminent peril of death or great bodily injury to self, family, or a member of the household when that force is used against another person, not a member of the family orhousehold, who unlawfully and forcibly enters or has unlawfully and forcibly entered the residence and the person using the force knew or had reason to believe that an unlawful and forcible entry occurred.
   As used in this section, great bodily injury means a significant or substantial physical injury.