While there is no explicit prohibition against acts epitomizing human limits of degeneracy, like cannibalism, necrophilia and pedophilia, in none of the canons of the three main Abrahamic religions, is it possible to argumentate with legitimate accuracy that during Mosaic times, such acts would be punished with death, even if no prohibition is clearly made of them in any law? Isnt their heinousness sufficient to hypothesize that capital punishment was meted out?
Rav Kook actually suggests something in that direction, but even more so: that the Torah, for example, does not explicitly cite a prohibition against cannibalism, for when the Torah was given 3,333 years ago, mankind, as a whole (at least the Jewish people whom the Torah is addressing), had already morally and spiritually matured to the extent that they were naturally disgusted with the idea, so there was no need to specifically address the repugnant issue, and no need to deter with punishments ("Vision of Vegetarianism", 4, although it should be noted that cannibalism does fall under several more general prohibitions, for there’s a positive (aseh) prohibition to eat only kosher animals (Rambam, Ma’achalot Asurot, 2, 3; Rama Y.D. 79, 1; Bach, etc.). Additionally, there’s a prohibition on defiling or using a dead human body (Y.D. 349), and also, we are prohibited from eating anything disgusting (Bal Tishaktzu, Shulchan Aruch Y.D. 116, 6). Accordingly, one could suggest a similar idea regarding other issues, as well. On the other hand, if theoretically mankind were ever to "slip", even temporarily and revert to such disgusting actions, the Sanhedrin and/or government have the power, if they see necessary, to institute the death penalty to help deter and uproot hideous crimes.