Widow: Murdered anti-ISIS filmmaker knew they would kill him

Boshra Kashmar lost her husband a month ago. Naji Jerf was shot in broad daylight, on a busy street in southern Turkey, near the Syrian border.

"It was a nightmare, yes. I'm trying all the time to wake up and find him, standing there, and joking, laughing," she told CBS News.

Jerf was a documentary maker who showed what life is really like under ISIS.

Kashmar told CBS News her husband received death threats from ISIS, though the extremists haven't claimed responsibility for his murder.

Bushra Kashmar at the burial of her husband, slain Syrian filmmaker Naji Jerf Sima Diab/BuzzFeed News

"He was telling me all the time, 'I hate the sound of bullets. I hate it very much. I know they are not going to kill me by the knife. They will gun me.' He knew."

Jerf sometimes worked with a group known as "Raqqa is Being Slaughtered Silently." Their citizen journalists risk their lives to report from inside the city of Raqqa, the so-called ISIS capital.

The group's website includes accounts not just of public executions, but also of extortion, bread lines, and how ISIS stops people from escaping the city. All of it reveals that Raqqa is far from the paradise that ISIS claims.

Naji Jerf and his wife Boshra Kashmar

To stop the truth getting out, ISIS has hunted down and murdered the group's activists, even when they're over the border in Turkey.

Mohammad Mosaraa is a former high school math teacher who helped found the Raqqa group and later fled to Turkey, where the death threats followed him.

"We've become numb," he said. "It's not easy to talk to your friends at night, and discover the next morning that they've been killed."

Mohammad Mosaraa CBS News

"Every time I go outside I have the feeling I'm being followed," Mosaraa continued. "But I need to stay alive, keep getting the word out, and not give in to ISIS."

Mosaraa left Turkey on Wednesday, and is now seeking asylum in Europe. But he said that other activists from the group remain inside Raqqa, risking death to report what's happening to their city.

Boshra Kashmar is also seeking asylum in Europe, but still can't bring herself to tell her youngest daughter, Emissa, that her father is gone.

"He said before, 'I don't want to die, I don't want to be arrested, I want to live and to do everything I can...'"