כָּל־מַ֨כֵּה־נֶ֔פֶשׁ לְפִ֣י עֵדִ֔ים יִרְצַ֖ח אֶת־הָרֹצֵ֑חַ וְעֵ֣ד אֶחָ֔ד לֹא־יַעֲנֶ֥ה בְנֶ֖פֶשׁ לָמֽוּת׃
Whoso killeth any person, the murderer shall be slain at the mouth of witnesses; but one witness shall not testify against any person that he die.
Read midrashic interpretation of Numbers 35:30: and classical rabbinic exegesis.