Can a Single Witness Sway a Capital Trial

One witness may not respond, whether in favor or against, according to the opinion of Rabbi Yosei bar Yehuda. He may respond in favor but not against. What is the reason for Rabbi Yosei bar Yehuda's opinion? It is derived from the fact that one witness may not respond in a capital case, as he does not respond to establish guilt but may respond in favor. The Rabbis disagree because it appears as if he is interfering with his testimony. And what do the Rabbis derive from the phrase "lamut, to death" (to death)? They apply it to include one of the disciples, as it is taught: One of the witnesses says, "I have something to teach regarding him in favor." How do we know that his words are not heard? The verse states, "ve-ed echad lo yaaneh, and one witness shall not answer" (one witness may not respond). How do we know that this includes one of the disciples who says, "I have something to teach regarding him in favor [or against]"? How do we know that his words are not heard? The verse states, "echad lo yaaneh, one shall not answer" (one may not respond). One witness may not respond in a capital case, but may respond in an oath case. The phrase "ve-ed echad, and one witness" (one witness) refers to a person who built his father's house. Wherever it says "ed, witness" (witness), it includes two witnesses until the verse explicitly singles out one witness. "In all your settlements" includes both in the land and outside the land. One might think that even cities of refuge should follow the same rules in both the land and outside the land, therefore it is stated "be-khol moshvoteikhem, in all your settlements" (in all your settlements) to teach that the courts operate in the land and outside the land, but cities of refuge are only applicable in the land.