The Auschwitz Institute for the Prevention of Genocide and Mass Atrocities (AIPG) is proud to present a new resource on transitional justice for the atrocity prevention community. The result of a research project supported by the United Kingdom’s Department for International Development_, Truth Commissions and Their Contributions to Atrocity Prevention_ fills a gap in existing scholarship by examining the ways that these important mechanisms for transitional justice are able to advance prevention at the national level. In consultation with a diverse team of international experts, Dr. Kerry Whigham, the project's principal researcher, provides insight into how and when truth commissions contribute to mass atrocity prevention. Using findings obtained through a mixed methodological framework, the project research team examined differing outcomes among and between 50 truth commissions (34 of which the research team judged to have been “legitimate”) and 54 cases where a large-scale outbreak of violence had ended without the establishment of a truth commission. The quantitative analysis of this project component is complemented and contextualized by a qualitative element, in which 8 truth commissions from 7 countries were considered for their effectiveness in mitigating a variety of specific risk factors. Among the findings made by the expert research team, analysis using modeling from the Atrocity Forecasting Project by the Australian National University revealed that, while an overall reduction of risk for atrocities appeared in all post-atrocity scenarios, “**Cases that implemented a truth commission… saw a 46.1% greater reduction in overall risk, on average over time, compared with those cases that did not implement a truth commission.**” Within this context, the report provides extensive and nuanced insight into the degree to which a wide range of individual atrocity risk factors relating to governance, economics, and social fragmentation were affected by the existence or absence of a truth commission. Using these conclusions, the authors of _Truth Commissions and Their Contributions to Atrocity Prevention_ compiled a set of 14 guiding principles for the design and establishment of truth commissions that reflect the priorities of an atrocity prevention agenda. The guiding principles are organized around five crucial points of intervention — stages at which the use of a preventive lens could shape how a truth commission is formed and how it operates. These stages include the truth commission’s mandate, structure, implementation, recommendations, and follow-up. By integrating these principles, government officials looking to create truth commissions can maximize the potential for these bodies to contribute to preventing atrocities and the recurrence of large-scale violence. Please to access a downloadable PDF copy of _Truth Commissions and Their Contributions to Atrocity Prevention_. An executive summary of the report is available . Spanish and German-language translations of the document will be made available in the near future.