The declassified information was compiled from open-source materials ranging from videos to on-the-ground accounts, geospatial intelligence, U.S. signals intelligence, and physiological samples from attack victims.
The attack came from Su-22 fixed-wing aircraft out of the Shayrat airfield hit in subsequent U.S. strikes, the report says; the planes were in the Khan Shaykhun area for 20 minutes before the first report of a chemical attack came in, and left soon after. The administration also has "information that suggest that personnel historically associated with the chemical weapons program were at Shayrat airfield in late March preparing for this attack," and these people were there again on the day of the attack.
The U.S. has confirmed the agent used in the attack was sarin, from testing on the victims and from symptom reports as well as "leakage around the actual weapon that we think the sarin came from." Emergency personnel suffered exposure symptoms from coming into contact with contaminated victims.
A hospital treating attack victims was struck by conventional weapons about six hours after the chemical attack.
On hoax theories, the White House official said the "absolute massive data we have in all the different vehicles -- we've gotten it from open-source videos, to victim accounts, to imagery, to signals intelligence, is just too massive for really any -- any intelligence organization to fabricate in that short a period of time; we just think that's not a feasible explanation." Intel agencies have confirmed that videos distributed of the attack were filmed at the time and in the locations claimed. |