Human Rights Watch report on Syria: Assad's govt. dropped the chemicals
Here's a link to the 22 page report documenting evidence for their conclusion that the chemical attack was carried out by the government.
http://www.hrw.org/node/118725/
Here's the press release:
http://www.hrw.org/news/2013/09/10/syria-government-likely-culprit-chemical-attack
(New York) – Available evidence strongly suggests that Syrian government forces were responsible for chemical weapons attacks on two Damascus suburbs on August 21, 2013. These attacks, which killed hundreds of civilians including many children, appeared to use a weapons-grade nerve agent, most likely Sarin.
The 22-page report, “Attacks on Ghouta: Analysis of Alleged Use of Chemical Weapons in Syria,” documents two alleged chemical weapons attacks on the opposition-controlled suburbs of Eastern and Western Ghouta, located 16 kilometers apart, in the early hours of August 21. Human Rights Watch analyzed witness accounts of the rocket attacks, information on the likely source of the attacks, the physical remnants of the weapon systems used, and the medical symptoms exhibited by the victims as documented by medical staff.
“Rocket debris and symptoms of the victims from the August 21 attacks on Ghouta provide telltale evidence about the weapon systems used,” said Peter Bouckaert, emergencies director at Human Rights Watch and author of the report. “This evidence strongly suggests that Syrian government troops launched rockets carrying chemical warheads into the Damascus suburbs that terrible morning.”
The evidence concerning the type of rockets and launchers used in these attacks strongly suggests that these are weapon systems known and documented to be only in the possession of, and used by, Syrian government armed forces, Human Rights Watch said.