Numbers 35:17-19

17If he struck his victim down [intentionally] with a stone in hand, which may cause a person to die, and he died, he is a murderer; the murderer shall certainly be put to death.

18Or if he struck his victim down [intentionally] with a wooden object in hand, which may cause a person to die, and he died, he is a murderer; the murderer shall certainly be put to death.

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