One of the obstacles faced by law enforcement officials in uncovering criminal acts is the limitation of evidence related to the criminal acts that occurred, where one of the evidence that can be used by law enforcement officials is the testimony of the Justice Collaborator to uncover other perpetrators and criminal acts that occurred as stipulated in Law Number 13 of 2006 concerning the Protection of Witnesses and Victims, amended by Law Number 31 of 2014. However, in practice, the criminal acts disclosed by the Justice Collaborator are general criminal acts and not specific criminal acts as regulated in the law so that they can provide legal uncertainty and justice. This research is normative legal research, with a legislative approach and a case approach. The results of the research are, First, the regulation of Justice Collaborator is specifically regulated in Law Number 13 of 2006 concerning the Protection of Witnesses and Victims, amended by Law Number 31 of 2014, but the regulation can only be applied to certain criminal acts regulated in the law. Second, the judge's consideration in imposing a verdict against the Justice Collaborator for the crime of murder in the case of the South Jakarta District Court Decision Number 798/Pid.B/2022/PN.Jkt Sel dated February 15, 2023, namely the criminal act revealed by the defendant Mr. Richard Eliezer Pudihang Lumiu can be categorized as a certain criminal act, the defendant is not the main perpetrator, the defendant plays a role in uncovering the criminal act, A request from a friend of the court to uphold justice, and the existence of repentance from the defendant.