Plato, Laws 873b

τοιούτων νομοθετεῖ, Προρρήσεις μὲν τὰς περὶ τῶν νομίμων εἴργεσθαι καὶ ἐγγύας τὰς αὐτὰς εἶναι καθάπερ ἐρρήθη τοῖς ἔμπροσθεν· ἐὰν δέ τις ὄφλῃ φόνου τοιούτου, τούτων κτείνας τινά, οἱ μὲν τῶν δικαστῶν ὑπηρέται καὶ ἄρχοντες ἀποκτείναντες, εἰς τεταγμένην τρίοδον ἔξω τῆς πόλεως ἐκβαλλόντων γυμνόν, αἱ δὲ ἀρχαὶ πᾶσαι ὑπὲρ ὅλης τῆς πόλεως, λίθον ἕκαστος φέρων, ἐπὶ τὴν κεφαλὴν τοῦ νεκροῦ βάλλων ἀφοσιούτω τὴν πόλιν ὅλην, μετὰ δὲ τοῦτο εἰς τὰ τῆς χώρας

The warnings of exclusion from customary places, and the sureties, are the same as those prescribed for former cases; and if any man be convicted of such a murder, and of having slain any of the persons named, the officers of the judges and magistrates shall kill him and cast him out naked at an appointed cross-roads outside the city; and all the magistrates, acting on behalf of the whole State, shall take each a stone and cast it on the head of the corpse, and thus make atonement for the whole State; and after this they shall carry the corpse to the borders of the land and cast it out