Two Massachusetts Institute of Technology scholars have issued a report putting the assertion that the Syrian government gassed it's own people into serious question. One author, Richard Lloyd is a former UN Weapons Inspector. The other, Theodore Postol is an MIT Professor. They state the following.
Sarin gas "Could not possibly have been fired at East Ghouta from the 'heart', or from the Eastern edge, of the Syrian government controlled area shown on the intelligence map published by the White House on August 30, 2013."
I won't make their case. Judge for your selves.
It supports misgivings I had at the time. The maladroit timing of the supposed attack made no sense from the regime's perspective. It was a windfall for the anti-regime rebels who almost got American armed backing because of it. Now that the rebellion has metastasized into a perfect babel of armed bands, it's lucky that we did not get hoodwinked into supporting this swan-dive into armed madness.