"The examination showed a few retouches," says Antonin Thuillier, AFP's Tungstene specialist. "The colors have been over-saturated, perhaps to better highlight the pools of blood. The jihadists' faces have been darkened (see red circle, above). Finally there's some doubt around the smoke in the background. The red spots, in the image below, show two areas of the photo that are identical. The Photoshop clone tool could have been used to hide something behind, or perhaps even some dust on the camera sensor."
The task is complicated by the fact that this type of photo circulates widely online before it is picked up by journalists. Every user or web site could change the image in a myriad of ways, such as adding watermarked logos or commentaries before republishing the picture. "When I find an interesting picture, I try to go back to the original," says Baz. "And if I can't do that, I reframe the image to remove the elements without news value."
Originally, the photo published online contained Arabic phrases. The first Arabic phrase says it is an "Assad al-Rahman al Bilawi alias Abu Abd al-Rahman" operation, the name of a jihadist leader killed by Iraqi forces in Fallujah. The second phrase gives more details: "The liquidation of members of the Safavid army who were fleeing in civilian clothes." (The Safavid dynasty ruled Iran for hundreds of years and converted to Shiite Islam and converted many populations during their conquests. "Safavids" is the nickname given to Shiites by extremist Sunnis.)
In the case of the photo at the top of this page, "the manipulations don't seem to have been done to significantly alter the photo's informational content," says Thuillier. There are no extra bodies or militants added by Photoshop. AFP therefore published the photo, along with a warning alerting clients to possible retouches and adding clearly that this was a photo pulled from the Internet, making it impossible to independently verify the date and location of the image.
"Of course, Tungstene can't detect photos that have been wholly staged," adds Thuillier. "If the jihadists had decided to pile bodies here from another location, or even if people are lying on the floor and pretending to be dead to make the scene more terrifying, the software can't detect that."
But the likelihood of this being staged is low, says Baz. Considering the type of violence known to have been perpetrated by ISIL over recent months in Iraq and Syria, it seems more likely that this was a real event.
"The jihadists don't need to stage incidents," says the photographer, who has covered conflicts in the Middle East and elsewhere for nearly 30 years.