ISIS militant who allegedly let girl die of thirst faces trial in landmark case Jennifer W. was allegedly a member of the terror group's "morality police."

MILAN, Italy -- A trial is now underway in Munich against a 27-year-old German convert to Islam who is accused of allowing a 5-year-old Yazidi girl to die of thirst in the scorching heat in Iraq.

It is the first prosecution for crimes of ISIS militants against Yazidi victims and may set a precedent for forthcoming cases.

If convicted by Munich state court, the defendant, identified as Jennifer W., faces life in prison for weapons offenses, joining a terrorist group, war crimes and murder.

Jennifer W. and her husband are also accused of enslaving the young girl in ISIS-held territory in Iraq.

The co-plaintiff and witness in the case is the girl's mother, who was also held captive by Jennifer W. and her husband. She is being represented by international and human rights lawyer, Amal Clooney, among others.

The start of the case is a landmark for Yazda, a global Yazidi non-governmental organization that helped identify and locate the girl’s mother.

“We have been waiting for this moment to happen – to see that this being discussed legally in the court where there is a criminal perpetrator,” Ahmed Khudida Burjus, director of Yazda, told ABC News.

“The most heinous crimes are what [ISIS] did with women and girls and children, where they used them for sex slaves and abused them psychologically, physically and sexually," he said, while stressing that the thousands of currently detained ISIS fighters should similarly be held responsible for their crimes.

The Yazidi people are an Iraqi ethnic and religious minority who were heavily targeted by the Islamic State. The United Nations called the ISIS assault on the Yazidi’s ancestral homeland in 2014 a genocide, noting that of the thousands captured, men and boys were either forced to fight or executed if they did not convert, according to The Associated Press. Women and girls were sold into slavery.

According to a statement put out by federal prosecutors, Jennifer W. was born in Lower Saxony, quit school in 8th grade and converted to Islam in 2013 before making her way to the Islamic state in 2014 where she “immediately joined the decision-making and command structure of the IS."

As a part of the group’s “morality police,” she patrolled parks in Fallujah and Mosul armed with a Kalashnikov-style assault rifle, a pistol and explosives vest, looking to punish women who did not confirm with the extremist group’s strict dress code, according to prosecutors.

In the summer of 2015, her husband, an Islamic extremist fighter, “purchased” the 5-year-old Yazidi girl and enslaved her and her mother in the household. When the child wet the bed, the defendant’s husband made her stand in the scorching sun as punishment, where it was 113 degrees Fahrenheit outside.

“The accused allowed her husband to do it, and did nothing to save the girl," prosecutors wrote in the statement.

While trying to renew her identity papers in Turkey in 2016, Jennifer W. was deported to Germany and eventually taken into custody after an investigation into her activities in 2018. According to German newspaper Der Spiegel, Jennifer W. was arrested after talking about her experiences, including the girl's death, during a ride in a car with a man who said he wanted to take her back to the Islamic State. That car was, in fact, bugged, and the man was an undercover police officer.

“Yazidi victims of genocide have waited far too long for their day in court. I am grateful to the German prosecutors who I have worked with for their commitment to holding ISIS members accountable for their crimes. And I hope that this will be the first of many trials that will finally bring ISIS to justice in line with international law,” Clooney wrote in a statement released by her office.