Totalitarian, dictatorial and repressive regimes may attempt to hide or destroy evidence of their abuses. A lack of evidence prevents perpetrators of crimes from being held accountable when the oppressive regime is dismantled. In the wake of these regimes, victims must come to terms with what happened to them. But what are the implications when records documenting acts of mass violence are destroyed and little evidence of the crimes is left? This research examines the importance of societies protecting documentation of the past in order to prevent collective forgetting or denial, ensuring that memory of past events remains. Through an extensive survey of the literature, many cases of the destruction of records documenting acts of mass violence were identified. In addition to presenting a mapping of nations where such acts have occurred, two are examined in detail: East Germany after the fall of the Berlin Wall and post-apartheid South Africa.