I read Thomas Wright's Impunity, Human Rights, and Democracy: Chile and Argentina, 1990-2005 (2014) for review in an academic journal. Here's a sample:
Thomas Wright has written a well-researched and succinct account of the efforts in Argentina and Chile to bring human rights abusers to justice after the transition from military to civilian rule. His goal is to understand how impunity eroded and justice advanced, even if slowly and imperfectly, in the face of stiff resistance from the military, its political allies, and even cautious policy makers.
He combines a synthesis of the existing literature with over forty of his own interviews and a variety of primary documents. The essential argument of the book is that human rights activists laid the initial groundwork in each country even when conditions were decidedly negatively due not only to the military’s political power but also to lack of funding. Yet at the same time, buoyed by increased attention from the United States, international human rights NGOs increased the scope of their work. Then a confluence of precipitating events gave new life to domestic activists and judges.
It's worth checking out.