TT #48 · Parashas Noach · Fourth Aliyah · Passuk 9:5
But for your own life-blood I will require a reckoning: of every beast I will require it; of man, too, will I require a reckoning for human life, of every man for that of his fellow man.
Torah Temimah points to the judicial parameters for a Ben Noach (Sanhedrin 57b).
E-Daf image — Sanhedrin 57b (size=3)
English: A Ben Noach is executed by a single judge and a single witness, without prior warning, on the testimony of a man and not of a woman, and even of a relative…
Custom (procedural differences for Noachide courts).
Noachide capital cases operate under relaxed evidentiary and procedural rules compared with Israelite courts.