1) THE DEFINITION OF A "HASRA'AS SAFEK"
QUESTION: Rebbi Shimon and the Rabanan disagree about what law is derived from the verse, "v'Arav Lo v'Kam Alav" -- "and he lies in wait for him, and rises up against him" (Devarim 19:11). Rebbi Shimon derives from this verse that in order for a person to be liable for murder, he must have had intention to kill his victim. If he had intention to kill one person but instead killed another, he is not Chayav Misah as a murderer. The Rabanan disagree and maintain that the verse teaches that if a person threw a rock into a crowd of Jews and Nochrim, and the rock killed a Jew, the perpetrator is not put to death by Beis Din.
The Gemara says that the Rabanan do not refer to a case in which there were nine Nochrim and one Jew in the crowd. In such a case, the murderer certainly would not be put to death for his act of killing, because most of the people in the crowd were Nochrim. The principle of Rov dictates that since there was a majority of Nochrim in the crowd, it is considered as though the murderer threw the rock into the crowd with intent to kill a Nochri, for which one is not Chayav Misah. The case also cannot be one in which there were five Jews and five Nochrim, because the principle of "Safek Nefashos l'Hakel" dictates that Beis Din judge him leniently and assume, out of doubt, that he intended to kill a Nochri and not a Jew. Rather, the Gemara explains that the Rabanan refer to a case in which the crowd was comprised of nine Jews and only one Nochri. Since the Nochri is "Kavu'a" ("in his place" and not separated from the others in the group), he gives the crowd a status of half-Jews and half-Nochrim because of the principle of "Kol Kavu'a k'Mechetzeh Al Mechetzeh Dami." The verse teaches that whenever there is a single item which is "Kavu'a" in a group (that is, it is "in its place" and is not separated from the other items of its kind), it is considered "k'Mechetzeh Al Mechetzeh" and consequently, in the case of a murderer, Beis Din must be lenient because of "Safek Nefashos l'Hakel."
Why does the Gemara say that the case of the Rabanan cannot be one in which there are five Jews and five Nochrim, because in such a case the principle of "Safek Nefashos l'Hakel" applies and the perpetrator may not be put to death? Even without the principle of "Safek Nefashos l'Hakel," Beis Din should not be able to kill the perpetrator, because the warning (Hasra'ah) that he received was not valid; it was a "Hasra'as Safek." When a doubt remains, at the time of the Hasra'ah, whether the prohibited act will result in punishment by Beis Din, the Hasra'ah is a "Hasra'as Safek." For example, when a person hits two men, one of whom is his father but he is unsure which one is his father, he is not Chayav Misah because the Hasra'ah that he receives is a Hasra'as Safek. Even if he is warned not to hit the first person "because if you hit the second one you will definitely have hit your father and you will be Chayav Misah," he still is not Chayav, because at the time of the first act it was not clear that the act would result in the death penalty. Since the Hasra'ah in the case of the Gemara here is only a Hasra'as Safek and is not valid, Beis Din cannot put the perpetrator to death.
The answer cannot be that the Gemara follows the opinion that a Hasra'as Safek is a valid Hasra'ah (Makos 15b), because according to that opinion, why is the killer not guilty in this case? According to that opinion, the Hasra'ah that a person receives before he hits two people (and it is not known which one of the two is his father) is a valid Hasra'ah. If the perpetrator is liable in a case in which he hits two people even though there is a doubt about which one is his father, then certainly the warning that he receives before he throws the rock into the crowd should be a valid Hasra'ah. (TOSFOS DH Iy Nami)
ANSWERS:
(a) TOSFOS answers that the Gemara here indeed follows the opinion that a Hasra'as Safek is a valid Hasra'ah. The reason why the killer is exempt in this case is that at the time he threw the rock into the crowd (and received Hasra'ah), there was no way that he could ensure that his act would make him Chayav Misah. Thus, the Hasra'ah in this case is not even a Hasra'as Safek. In contrast, in the case in which a person hits the first of two people, it is within his control to make sure that he will be Chayav Misah -- all he needs to do is hit the second person. Hence, the Hasra'ah in that case is considered a valid Hasra'ah, even though at the time that he performs the first act there is not certainty that he will be Chayav Misah (since it is not certain that he will perform the second act).
(b) The SHITAH MEKUBETZES in Kesuvos (15a) answers in the name of RABEINU ELIEZER MI'GURMAIZA (Worms) that the Gemara follows the opinion that a Hasra'as Safek is a valid Hasra'ah (like Tosfos), and that the Hasra'ah in the case of the Gemara here is a valid warning (not like Tosfos), and the thrower should be Chayav Misah. The Gemara does not mean that Beis Din should be lenient and spare the life of the perpetrator (as Tosfos understands the Gemara). Rather, the Gemara means to ask a rhetorical question, and not to make a statement: once the perpetrator has been warned that he might kill a Jew through his act, should he not take into account the possibility that he might kill a Jew and treat lightly the risk to a Jew's life? It is obviously a good Hasra'ah, and therefore it cannot be the case that the verse excludes according to the Rabanan. (Y. Montrose)
(c) The YAD RAMAH explains that when the rock killed one of the people in the group, it was not possible to determine whether it was a Jew or Nochri that was killed. The Gemara's question is that if half of the people in the group were Jews and half were Nochrim, why should the thrower be Chayav Misah? It is obvious that he cannot be killed, since there is an equal chance that the victim is not a Jew. Rather, it must be that most of those present were Jews, and that is why one might have thought that the thrower is Chayav Misah even though the identity of the dead man could not be determined. The Gemara concludes that the thrower nevertheless is exempt because of the rule of "Kavu'a."

79b----------------------------------------79b

2) A MURDERER WHO BECAME LOST IN A CROWD
QUESTIONS: The Mishnah states that "a murderer who became mixed with others" exempts everyone in the crowd from punishment (as the Gemara will explain). Rebbi Yehudah argues and says that all of the people are placed into a "Kipah." RASHI explains that a Kipah is a place of confinement where criminals are incarcerated and fed barley until their stomachs expand and rupture (as the Gemara on 81b explains). The Gemara inquires as to the identity of the other people in the crowd. The Mishnah certainly does not refer to a group of innocent people, for in such a case it would be obvious that, according to the Rabanan, they are exempt from punishment. Similarly, according to Rebbi Yehudah, it is obvious that innocent people would not be placed in a Kipah and caused to suffer a terrible death.
Rebbi Avahu answers that the Mishnah refers to a murderer who escaped from his trial before he was sentenced, and he became mixed in a crowd of other murderers who were already sentenced to death. The Rabanan maintain that since Beis Din may sentence a person to death only in that person's presence, Beis Din cannot sentence to death the runaway murderer in absentia. Consequently, the entire crowd is set free out of doubt which one is the one who is exempt. Rebbi Yehudah says that even though Beis Din cannot administer the death penalty that they deserve, Beis Din still may execute them in the manner of the Kipah.
(a) Does this Halachah apply to all cases of uncertain identity involving people who are supposed to be killed, and not just to a case involving murderers?
(b) Is there a difference between a case in which only one person was not sentenced to death, and a case in which a majority of the people in the crowd were not sentenced? Also, according to the Rabanan, are all of the murderers in the group entitled to go home as free men?
ANSWERS:
(a) The TORAS CHAIM writes that the Mishnah specifically refers to a case involving a murderer who became lost in a crowd of other murderers, and not to a case involving a person who was being tried for another violation for which one is Chayav Misah, such as for desecrating Shabbos. Only when the others in the crowd are murderers does Rebbi Yehudah maintain that Beis Din administers the punishment of Kipah. In order for the Mishnah to express the opinion of Rebbi Yehudah, it discusses a case of murderers, the only case in which his opinion applies.
(b) The ME'IRI quotes two opinions with regard to the Halachah in a case in which only a minority of the people in the crowd was sentenced to death, and a majority was not sentenced to death. One opinion maintains that the Halachah is the same. Another opinion maintains that in such a case Rebbi Yehudah would agree that Beis Din does not put them all into a Kipah, and that only when most of them are convicted murderers does Beis Din put them into a Kipah.
The MARGOLIYOS HA'YAM cites an opinion which infers from the wording of the RAMBAM that he is of the latter opinion. The Rambam (Hilchos Rotze'ach 4:7) rules like the Rabanan who say that Beis Din does not kill the people in the crowd. However, the Rambam adds that the people are kept incarcerated. The Rambam elsewhere (Hilchos Sanhedrin 14:7) discusses a similar case involving two people, in which one person was sentenced and the other was not. The Rambam there also rules like the Rabanan and does not say that both people are put to death. However, he omits his ruling about keeping them incarcerated. It must be that the Rambam understands that the Rabanan require that the entire group be kept in confinement only when a majority of the people in the group were convicted. When a minority (or half) of the people in the group were convicted, the law does not require incarceration. (Presumably, the Rambam would explain the opinion of Rebbi Yehudah in the same manner, that in a case in which there are only two murderers Rebbi Yehudah does not require that they be placed in a Kipah.)
The Acharonim discuss the source for the Rambam's ruling that all of the people in the crowd are incarcerated. The KESEF MISHNEH explains that the Rambam derives this requirement from a law in the Torah. The Torah teaches that Beis Din is to jail a person who hit another person with a potentially fatal blow until it becomes clear that the victim will survive (Kesuvos 33b, based on Shemos 21:19). Similarly, Beis Din is to jail murderers who cannot be executed due to a technicality.
The ARUCH LA'NER questions the Kesef Mishneh's explanation of the Rambam's source. The law that Beis Din jails a person who hit another person until it becomes clear that the victim will survive is not related to the case of the Gemara here that the Rambam is discussing. In the Torah's case, Beis Din must jail the perpetrator temporarily, until the doubt at hand resolves itself (by the victim either recovering or dying). In the Gemara's case, however, the identity of the murderer who was not sentenced to death might never be clarified, and thus perhaps in such a situation the Torah does not advocate imprisonment.
The Aruch la'Ner, therefore, explains that the Rambam's source is a Yerushalmi in which Rebbi Yochanan says that the case of the Mishnah involves ordinary people (and not murderers). The Rambam understands that according to that opinion, if the case would involve criminals, then even the Rabanan would agree that they are placed in a Kipah.
The Aruch la'Ner also understands that the Rambam disagrees with Rashi about the definition of "Kipah" in our Mishnah. He does not agree that it is a small confinement area in which the criminals are fed barley that eventually kills them, but rather he maintains that it is a jail, a place to keep the criminals imprisoned. (Y. Montrose)