The "Gemara" cited the Torah's requirement for corroborating witnesses in to support the Mishnah's prohibition of circumstantial evidence in capital cases. The Mishnah reported that they admonished witnesses in capital cases not to testify based on conjecture (that is, circumstantial evidence) or hearsay, for the court would scrutinize the witnesses' evidence by cross-examination and inquiry. The "Gemara" reported that the Rabbis taught that the words "based on conjecture" in the Mishnah meant that the judge told the witness that if the witness saw the defendant running after the victim into a ruin, and the witness pursued the defendant and found the defendant with bloody sword in hand and the victim writhing in agony, then the judge would tell the witness that the witness saw nothing (and did not actually witness a murder). It was taught in a Baraita that Rabbi Simeon ben Shetach said that he once did see a man pursuing his fellow into a ruin, and when Rabbi Simeon ben Shetach ran after the man and saw him, bloody sword in hand and the murdered man writhing, Rabbi Simeon ben Shetach exclaimed to the man, "Wicked man, who slew this man? It is either you or I! But what can I do, since your blood (that is, life) does not rest in my hands, for it is written in the Torah (in ) 'At the mouth of two witnesses . . . shall he who is to die be put to death'? May He who knows one's thoughts (that is, God) exact vengeance from him who slew his fellow!" The "Gemara" reported that before they moved from the place, a serpent bit the murderer and he died.