Okla. Stat. tit. 21, § 21-711: Manslaughter in the first degree defined

Homicide, a Class A2 felony offense, is manslaughter in the

first degree in the following cases:

1. When perpetrated without a design to effect death by a

person while engaged in the commission of a misdemeanor;

2. When perpetrated without a design to effect death, and in a

heat of passion, but in a cruel and unusual manner, or by means of a

dangerous weapon; unless it is committed under such circumstances as

constitute excusable or justifiable homicide;

3. When perpetrated unnecessarily either while resisting an

attempt by the person killed to commit a crime, or after such

attempt shall have failed.