By: Rav Yitzchak Grossman
Posted with permission of the Journal of Talmudic Law & Finance and the Bais HaVaad Institute of Talmudic Law
“And Moshe was afraid” – in addition to the Peshat that he feared the temporal consequences of the discovery of his vigilante execution of the Egyptian, Rashi cites a Medrash that what worried him was the realization that Israel contained “villains, informers – he said ‘now, perhaps they are not worthy of redemption’”.
The topic of Mesirah in the modern era is a very fraught area of Halachah. On the one hand, Shas and Poskim have traditionally condemned Mosrim in the most drastic terms: they are included (along with apikorsim and those who have sinned and caused others to sin) in the list of those who suffer for an extended duration in Hell, are worse than apostates, and cannot (at least according to some opinions) ritually slaughter animals, or write Sifre Torah or Gittin. And, of course, they may be killed “anywhere, even in contemporary times” after being duly warned, if they are threatening to inform. But on the other hand, it is clear that much of the Halachic literature on the topic was written in the context of regimes that were vastly more ruthless, brutal and unprincipled than modern Western democracies, and of Jewish communities that had much more autonomy and capability of internal regulation than today’s post-Enlightenment diffuse and acculturated ones.
We cannot hope to provide a systematic, comprehensive perspective on this topic in the brief span of this essay; we shall merely briefly discuss some basic questions in this area.
It is crucial to understand that the literature on Mesirah really comprises two very different strands of Halachah. First, a Moser is a Mazik; although the harm caused is indirect, indirect harm is still prohibited, and the Poskim explain that the ex-post-facto liability is due to Mesirah falling under the rubric of Garmi. Additionally, the Gemara considers a Moser to be a Rodef (hence the aforementioned license for his extra-judicial execution); as Rosh explains: “they have no mercy on him – today they take some [of his property], and tomorrow all of it, and in the end they torture his soul and kill him in order that he confess, perhaps he has more property, and so [the informer] is a Rodef, whom it is permitted to kill to save [the victim]“.
Some therefore argue that in the context of civilized societies, the aspect of Rodef may no longer apply, but Mesirah may still be considered a tort and therefore prohibited, and the Moser still held liable for his Hezek.
Conversely, it is unclear whether the tort aspect of Mesirah holds where the loss suffered by the victim is considered legitimate, such as where he is actually liable for the money taken from him according to native Halachah or the principle of Dina De’Malchusa Dina. While Mesirah may still be prohibited, for various reasons, ab initio, there may be no ex post facto liability.
A related question is whether Jews may cooperate with the secular criminal justice system in the apprehension, prosecution and punishment of Jewish criminals. The Gemara relates that R. Elazar b. Shimon helped the government catch Jewish thieves, who were then executed, and while his colleagues disapproved, he defended his conduct; various Poskim have inferred from this passage that cooperation with the criminal justice system is permitted even where it can result in the death of the criminal.
 Rosh Ha’Shanah 17a, and see Shach CM 388:53.
 Shach ibid. and #62.
 Shach ibid., citing Shulchan Aruch YD 2:9.
 Shach ibid., citing Shulchan Aruch YD 281:3.
 Even Ha’Ezer Siman 123: Get Pashut #7 s.v. le’inyan mumar u’malshin, and Yeshuos Ya’akov (short) #9, cited in Pis’chei Teshuvah #4.
 The reasons for this are quite subtle and not entirely clear, and well beyond the scope of this essay; see Tosafos Bava Kama 22b s.v. zos omeres, Rosh ibid. Ch. 9 Siman 13 and Bava Basra Ch. 2 Siman 17, Mordechai Bava Kama remez 119, Kuntres Dina D’Garmi of Ramban, and Resp. Terumas Ha’Deshen I:315.
 Bava Kama 117a.
 Rosh Bava Kama ibid. end of Siman 27.
 See, e.g., Aruch Ha’Shulchan CM 388:7, Resp. Tzitz Eliezer 19:52:5:1, Pis’chei Choshen (Nezikin) Ch. 4 n. 1
 This question is discussed by many Poskim, including: Maharam Mirzburk, as codified by Rema (CM 388:12), Resp. Maharashdam CM end of #55, Resp. Divrei Rivos #83, Resp. Mahari Ibn Lev 2:54, Shach 388:20.
 Bava Metzia 83b.
 Resp. of Rashba: New Responsa From Manuscript #345 (cited in Beis Yosef CM end of siman 388), III:393 (cited in Beis Yosef siman 2 mechudash 2, V:238, Resp. of Maharam Shick CM #50, R. Broyde’s paper, and Rabbi J. David Bleich, “Jewish Law and the State’s Authority to Punish Crime”, in Contemporary Halachic Problems Vol. IV Ch. IV pp. 62-91. But see R. Avrohom Noach Taplin, Nehorai (5767, p. 822), who argue vigorously that other Rishonim forbid such cooperation. See also the responsa of major contemporary Poskim on the topic of reporting child abusers to the authorities in “Kuntres Dam Re’echa”, Yeshurun Volume 15 p. 734.