A justice collaborator is one of the actors who can be invited to work together, namely someone who has good character so that he can have the status of a witness, reporter or informant so that from his statement he can provide assistance such as providing important information, strong evidence or information given to law enforcement to use in reveal a criminal act that occurred, this study aims to find out how the arrangement for granting justice collaborators in Indonesia and also for what are the judge's considerations in imposing criminal sentences for justice collaborators in decision number 798/Pid. B/2022/PN. Jkt. South. This research method uses normative juridical. The leniency of criminal penalties for justice collaborators refers to recommendations issued by the LPSK (Institute for the Protection of Witnesses and Victims). Results of Judge Considerations in Decision Number 798/Pid.B/PN.Jkt. South. in terms of mitigating the sentence of the defendant Richard Eliezer Pudihang Lumiu so that the criminal sentence given was lighter than the other defendants in the case of the Joint Murder against Brigadier Nofriansyah Yoshua Hutabarat or commonly known as Brigadier J, namely; The defendant is a witness to the perpetrator who cooperates (Justice collaborator), the defendant is polite in court, the defendant has never been punished, the defendant is still young, it is hoped that he will be able to improve his actions in the future.