Numbers 35:16-19

16‘1But if he struck him with an iron object, so that he died, he is a murderer; the murderer must be put to death.

17And if he struck him with a stone in the hand, by which he would die, and as a result he did die, he is a murderer; the murderer 2must be put to death.

18Or if he struck him with a wooden object in the hand, by which he would die, and as a result he did die, he is a murderer; the murderer must be put to death.

19The blood avenger himself shall put the murderer to death; he himself shall put him to death when he meets him.