Article 15(1)-(4) of the Rome Statute of the International Criminal Court outlines the process for the Prosecutor to initiate an investigation. It states that the Prosecutor may initiate an investigation on their own initiative or after receiving a referral from a State Party or the United Nations Security Council. The Prosecutor must first assess the information available to determine if there is a reasonable basis to proceed with an investigation. Additionally, the Prosecutor must notify the States Parties and the Security Council of their intention to investigate before proceeding.
