The suspect fled to Syria after the murders, but Turkish police caught him when he tried to return.
The Kurdish-Arab alliance is battling to oust ISIS from the city where it executed several Western hostages.
Pro-Kurd media shared footage of Syrians burning burqas and cutting their beards after the Syrian Democratic Forces defeated ISIS in an area of Raqqa.
Most oil and gas fields are under the control of U.S.-backed forces, despite Syrian military gains.
The American mission in Syria is simply one of killing ISIS. Keeping it dead is someone else's job.
Two Syrian activist groups with ties to the country's opposition also offered opposing claims about the Islamic State militant group leader's death.
The Islamic State militant group killed an activist from California, a U.S. Army veteran from New York and another YPG volunteer from the U.K.
Directed and produced by the Academy Award-nominated maker of Cartel Land, Matthew Heineman, City of Ghosts follows the journey of the citizen journalist group Raqqa is Being Slaughtered Silently.
The beneficiaries of America's "degrade and destroy" strategy will be Iran and Assad.
Every time we vaporize a terrorist leader, we vaporize all the intelligence in their brains.
The group is about to lose Mosul, most of Raqqa, and has already lost most of its funding.
The Syrian Observatory for Human Rights says the strike in Mayadin, eastern Syria, killed 44.
The group has lost a quarter of the eastern Syrian city within weeks.
The Syrian Observatory for Human Rights said the period between May 23 and June 23 saw 472 civilian deaths.
Kurdish militants are on the front lines of U.S.-led efforts to defeat the Islamic State militant group, but what happens when the battle's over?
Russia says the downing of the Syrian warplane was 'a cynical violation of Syria's sovereignty.'