http://syriapropagandamedia.org/working-papers/assessment-by-the-engineering-sub-team-of-the-opcw-fact-finding-mission-investigating-the-alleged-chemical-attack-in-douma-in-april-2018
A careful examination of these images leaves little doubt that the victims were murdered as captives. The staining of the victims’ faces by mucus flowing from their noses and mouths shows in at least some cases the mucus flowed up their faces towards the eyes. This implies that they were hung upside down while exposed to the agent. Bizarrely, the eyes of most victims appear to have been masked so that the eyes were not affected by gas or mucus. In a few victims there are visible strap marks suggesting that the eyes were protected by something like swimming goggles. A possible motive for masking the eyes may have been to make it less obvious that the victims had suffered prolonged exposure to an irritant gas.
We conclude that the staging of the Douma incident entailed mass murder of at least 35 civilians to provide the bodies at Location 2. It follows from this that people dressed as White Helmets and endorsed by the leadership of that organization had a key role in this murder.