Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Investigators Build Case for IS Crimes Against Yazidis Associated Press QASR AL-MIHRAB, IRAQ -- He was burly, with piercing blue eyes, and it was clear he was in charge when he entered the Galaxy, a wedding hall-turned-slave pen in the Iraqi city of Mosul. Dozens of Yazidi women and girls huddled on the floor, newly abducted by Islamic State group militants. He walked among them, beating them at the slightest sign of resistance. At one point, he dragged a girl out of the hall by her hair, clearly picking her for himself, a Yazidi woman -- who was 14 when the incident occurred in 2014 -- recounted to The Associated Press. This was Hajji Abdullah, a religious judge at the time and labeled one of the architects of the militant group's enslavement of Iraq's Yazidi religious minority, who rose to become deputy to IS leader Abu Bakr al-Baghdadi. He's believed to be the late al-Baghdadi's successor, identified only by the pseudonym Abu Ibrahim al-Hashimi al-Qurayshi. A group of investigators with the Commission for International Justice and Accountability is amassing evidence, hoping to prosecute IS figures for crimes against humanity, war crimes and genocide -- including Hajji Abdullah. Hajji Abdullah was previously accused of involvement in the slave trade, most notably in a wanted poster circulated by the U.S. setting a $5 million bounty on his head. But his prominence in the creation and oversight of the slave trade has never been spotlighted. "IS fighters didn't take it upon themselves to rape these women and girls. There was a carefully executed plan to enslave, sell, and rape Yazidi women presided over by the highest levels of the IS leadership," said Bill Wiley, executive director and founder of CIJA. "And in doing so, they were going to eradicate the Yazidi group by ensuring there were no more Yazidi children born." CIJA shared some of its findings with The Associated Press. The group, through IS documents and interviews with survivors and insiders, identified 49 prominent IS figures who built and managed the slave trade, as well as nearly 170 slave owners, including Western, Asian, African and Arab fighters. These also include top financiers, military commanders, local governors and women traders, many of them from the region neighboring the Yazidi community's villages. The AP also put together findings from IS's own literature, along with interviews with IS members, former slaves and rescuers, to establish how slavery was strictly mapped out from the earliest days, devolving into a free-for-all with fighters enriching themselves by selling Yazidi women as the group's power began to disintegrate. CIJA's focus now is to build cases that courts can use to try IS members for crimes against humanity or genocide. Countries can prosecute militants for individual rapes or torture or for membership in a terrorist group. But to prove higher charges, they would need the contextual evidence that CIJA provides, showing the crimes were part of a greater structure. "Practically every Daesh prosecution that has ever happened anywhere in the world is a material support case, a membership case," Wiley said, using an Arabic name for the group. "Prosecuting high crimes could serve as a counter-radicalization tool for IS supporters." In the first prosecution on charges of genocide against the Yazidis last month, a German court brought an Iraqi national to trial for enslaving a Yazidi woman and her 5-year-old, who was chained and left to die of thirst. Meanwhile, a U.N. investigative team said it has collected evidence from Iraq, including 2 million call records, that can strengthen cases of prosecution for crimes against the Yazidis. CIJA is sharing its findings from Iraq with the U.N. team and is pursuing more evidence from Syria, where IS made its last stand. The Syrian Kurdish authority holds perhaps the largest trove of material from the group, as well as some 10,000 of its members, including 2,000 foreign fighters, in detention. Investigators' steep challenge: documenting crimes committed over the course of four years against millions of people in different countries, while many IS members remain at large. In the Iraqi city of Mosul, for instance, the crimes took place among a population of nearly 2 million people over three years, including enslavement, attacks on dissidents, destruction of cultural and religious sites and training children in jihad. .