A transnational legal ordering (TLO) has emerged and settled since 1945 around capital punishment. In contrast with transnational legal orders in other domains of criminal justice, the death penalty TLO regulates activity that is not transnational but rather national or local. The analysis therefore explains abolition in domestic law, confronting the question of how abolition can occur domestically when publics almost universally favor retention. Two types of domestic institutions can make non-majoritarian death penalty abolition more likely: (1) proportional representation in the legislature and (2) courts that are independent of the political branches. Transnational influences can also enhance the likelihood of abolition, in particular, (1) the incentive of membership in regional organizations, and (2) the persuasive and socializing influence of international non-governmental organizations (INGOs). This chapter offers a novel means of measuring INGO influence and incorporates it in the analysis of data from about 150 countries. The analysis finds that proportional representation electoral systems, country-specific INGO attention, and regional effects increase the likelihood that a country will abolish the death penalty in a given period. Brief case studies illustrate the mechanisms highlighted by the broader analysis, including instances of both abolishers and non-abolishers.