A link to the Bellingcats interesting article of march 2015 with explanation how the team managed to geolocate the site where syrian defector "Caesar" took the pictures of the prisoners that have been tortured to death:
"Bashar al-Assad and his regime are suspected to be behind the disappearance of many thousands of persons in recent years, many of whom are presumed to have been tortured and killed. Following prisoners’ deaths, a team of forensic photographers would be dispatched to document the bodies of the victims of the Assad regime. Defectors have suggested that each corpse was meticulously documented, including wounds inflicted by firearms.
According to reports, at the onset of the Syrian crisis, the government would take the corpses of activists and prisoners to Hospital 607 at a military base in the Tishreen district of Damascus. As the death toll rose around the country, including among political prisoners and anti-Assad activists, the government made the decision to transfer the bodies of deceased prisoners to Hospital 601 in the Mazzeh neighborhood of Damascus so that the bodies of military personnel and prisoners would not be stored in the same location. This is according to a forensic photographer working for the Assad regime to document the mutilated corpses of the Assad regime’s victims who defected to the West and was given the codename “Caesar.”
In August 2013, in the process of defecting, Caesar smuggled some 55,000 photographs on thumb drives. Reports suggest that those images depict 11,000 victims of the Assad regime. By Caesar’s account, the bodies stored at Hospital 601 came from 24 prisons and security agencies. As the death toll of prisoners and anti-Assad activists and protestors soared, space for storing the corpses became so scarce that the bodies were sometimes stored outside.
On Tuesday, Bellingcat was alerted to the first geolocatable Caesar photo by @ArtWendeley. Given the graphic nature of the photo, Bellingcat has opted to censor portions of the image, but the original version shared with Bellingcat can be found here."
You can read the rest of the piece via the below link: