I'm (pleasantly) surprised you asked this question.
As I have stated many times before, I don't claim to know who did it. You and the US don't care about the chemical weapons or the people who died because of them. All you care about is creating an excuse that helps you achieve your political goals, just like you did with Iraq.
IMO if what you really care about is the chemical weapons, then Assad (thanks in part to Russia) has given up all of his stockpile of chemical weapons. Does that make him a better person? No. Does that make him lesser of a dictator? No. But in the issue of chemical weapons, the goal should be that we make sure this doesn't happen again, and Assad did what he should do. The reality is, right now, the only danger of using chemical weapons is coming from the other side, the side you're supporting, and ironically you don't seem to care about that.
Also the article I posted is not quoting me. It's quoting the intelligence service of an anti-Assad country, and they're clearly indicating that Assad didn't order the attack. It doesn't surprise me though that you choose to ignore these reports/facts, because like I said, you're not after the truth, you're just (knowingly or unknowingly) part of the US propaganda machine.