ISIS defector describes how 'Jihadi John' ran executions

A defector from the Islamic State terror group talked to Sky News about how militants prepared captives for executions, and the militant known as "Jihadi John" gave orders.

"Turkish man say 'put this camera there, change place there' but John [was] the big boss," an ISIS defector in Turkey said of Mohammed Emwazi, the 26-year-old Londoner featured in ISIS videos. "All time, all time say to all 'fastly, fastly, fastly, we should finish'. So respect him. Only he talks orders - others do."

The terrorist group reportedly staged mock executions to prepare hostages for being on camera, telling them in the rehearsals that they wouldn't be harmed.

Sky reports: "The execution rehearsals took place so that when the moment of death finally came, the hostages were not expecting to be killed and were relaxed to appeal for their release on camera."

The hostage-beheading videos have become an important part of ISIS propaganda. The videos get much media attention and are accessible to the world through YouTube and other video hosting sites.

Sky's source, who goes by the pseudonym "Saleh," says he was a translator for ISIS. He reportedly fled to Turkey to escape ISIS.

Saleh said that "John," recently identified as Emwazi, is reportedly the terror group's chief killer of foreign hostages.

The man said his job was to help convince the hostages they were safe.

"[Emwazi] would say to me 'say to them, no problem, only video, we don't kill you, we want from your government [to] stop attacking Syria. We don't have any problem with you; you are only our visitors,'" Saleh told Sky, adding that he knew the whole time the hostages would eventually be killed.

The hostages were also reportedly encouraged to become Muslim and given Arabic names to help them feel more relaxed among the militants.

Saleh's statements are in line with what a former CIA counterterrorism analyst wrote for The Washington Post in September. Aki Peritz explained that the hostages might appear so calm in the ISIS videos because they don't know they're about to be murdered. And statements from former ISIS hostages have corroborated the mock execution story.

Emwazi is believed to be responsible for multiple executions of Western hostages. Saleh confirmed his identity to Sky. Emwazi reportedly left Europe for Syria in 2012.