On May 25, 2022, the U.S. Department of State announced [3] the creation of the Atrocity Crimes Advisory Group (ACA) for Ukraine. Established jointly by the United States, European Union, and United Kingdom, the ACA is "aimed at ensuring efficient coordination of [the partners'] respective support to accountability efforts on the ground" in Ukraine. More broadly, it will support the work of the War Crimes Unit of the Office of the Prosecutor General (OPG) of Ukraine in its work. The ACA will also "provide strategic advice and operational assistance to OPG specialists and other stakeholders in areas such as collection and preservation of evidence, operational analysis, investigation of conflict-related sexual violence, crime scene and forensic investigations, drafting of indictments, and co-operation with international and national accountability mechanisms."  It will bring together a multi-national group of war crimes experts, currently based in Poland due to the security situation in Ukraine. In addition to acting as an advisor to the OPG, the ACA will also coordinate the creation of several Mobile Justice Teams to assist the OPG in its field investigations.