After bumping into this gem, I checked the source, CAPOTHAI.ORG

One article, "Who Killed the Red Shirts", makes for interesting reading.

If, after reading the "Red Shirt" piece, you wish see a wonderful little timeline of the events, you can continue to the site linked at the end of the report: http://www.factreport.go.th/

With a great resource like this, no wonder CRES feels no need for alternate opinions.