The research focuses on someone who has a role as justice collaborator in criminal act of muder, at the point of view of justice for the victim. The research discusses the implementation of laws about justice collaborator, focusing on one of criminal acts of murder that involved one justice collaborator witness in Indonesia. The method which is used is normative writing method. The urge of the research is that can the attendance of justice collaborator witness contribute to revealing a criminal act of murder and to fulfil justice value on lossing someone's life.