Twenty one page document on human rights in Syria, and a comprehensive review of the Houla massacre, detailing the government's claims and the opposition's claims. If one has an "opinion" on the Houla massacre derived from journalists (usually biased), this report contains facts and evidence where available. Although no firm conclusion can be drawn, one side is more likely to have committed the massacre.
http://www.ohchr.org/Documents/HRBodies/HRCouncil/RegularSession/Session20/COI_OralUpdate_A.HRC.20.CRP.1.pdf