We intend to show the role of the Public Prosecutor’s Office in the use of the rewarded cooperation, which has changed the understanding of the judicial process, legal evidence and the guarantees of the defendant. We approach the expansion of the power and action of the Public Prosecutor’s Office through bibliographical, documentary and media research (2017-2018). We analyzed the practices of operators in making agreements, investigations and generating judicial evidence based on observation and interviews with members of the MPF and the Rio de Janeiro Court of Justice (2017-2019). The agreements legitimize the anticipation of the constitution of evidence for the investigative phase, making it impossible for the defendants cited to defend themselves.