US 'has evidence of Syrian sarin use' but Bashar al-Assad remains undeterred by threats

There is definitive proof Bashar al-Assad used sarin gas against Syrian civilians, the US secretary of state, John Kerry, has declared.

http://metro.co.uk/2013/09/01/us-has-evidence-of-syrian-sarin-use-but-bashar-al-assad-remains-undeterred-by-threats-3945435/