No one holds out hope the victims, mostly poor fishermen who had gone to Libya to scratch out a living, are still alive. But several anomalies in the video, which was posted online Feb. 15, indicated to trained eyes that at least some of the production was done on "green screen" with background added later, perhaps to disguise the real location of the atrocity. A day after the clip went viral, Egyptian warplanes struck hard at an eastern port city near Tripoli, where the video appeared to have been shot.

“The ISIS' manipulation of their high-production videos has become commonplace,” said Veryan Khan, editorial director of the Florida-based Terrorism Research & Analysis Consortium. The murders likely took place in a studio, and the background image shown was likely from another location, the Bay in Sirte, a part of the Mediterranean Sea on the northern coast of Libya, according to Khan. There are several technical mistakes in the video that show it was manipulated, she said.

The most obvious, Khan said, is the speaker, he is much larger than the sea in both the close up and wide shots, and his head is bizarrely out of proportion, meaning he was filmed indoors and the sea added behind him, Khan said. In addition, the terrorists featured in the film look to be more than 7 feet tall, towering as much as two feet above their victims.

Hollywood horror film director Mary Lambert, who among her many film credits directed Pet Cemetery, analyzed the film for FoxNews.com and quickly concluded Khan was correct.

“The shot that seems really tampered with is the one with the really tall terrorists and the dwarf Christians,” said Lambert, also a professor at New York University's vaunted film school. “The close-ups of terrorists on the beach are most likely green screen.”