The current paper evaluates the interpretation that the realistic and idealistic school carries out to the transitional justice (JT) in societies with internal problems. As a case study, this developed the application of the model justice for peace in the Salvador from the Chapultepec agreement approval in 1992. A comparison between the Positivist and Realistic schools is presented at the beginning, in regards to the law conception, in order to relate the contributions that the realism school (North American and Scandinavian School) do to the legal theory. The article's main core describes the impunity to the perpetrated in the last twenty-five years, due to General law approval amnesty, that the legislative assembly does in 1993, as a response to the National reconciliation in 1992 that only benefited to the fighter of guerrilla group. Finally, after two decades later of implementing the JT, the constitutional chamber of the Salvador failed the General amnesty law unenforceability, affecting the peace negotiating parties, due to they should respond by against humanity crimes and HH. RR violation carried out between 1 Jun 1989 and 16 January 1992. [ABSTRACT FROM AUTHOR]