NET
21 One who beats an animal to death must make restitution for it, but one who beats a person to death must be put to death.
Darby
21 He that smiteth a beast [mortally] shall make it good; and he that smiteth a man [mortally] shall be put to death.
KJV
21 And he that killeth a beast, he shall restore it: and he that killeth a man, he shall be put to death.