αὐτόχειρ
I. "with one's own hand", Aesch., Soph., etc.: c. gen. "the very doer or author of" a thing, id=Soph., Dem.
II. absol., like αὐθέντης, "one who kills himself or one of his kin", Soph.: then, simply, "a murderer, homicide", id=Soph., Dem.; in full, τὸν αὐτ. τοῦ φόνου "the perpetrator of..", Soph.
III. as adj. "murderous", Eur.; πληγέντες αὐτόχειρι μιάσματι of brothers smitten by mutual slaughter, Soph.