"The six-page French document – drawn up by France’s military and foreign intelligence services and seen by Reuters – said it reached its conclusion based on samples they had obtained from the impact strike on the ground and a blood sample from a victim."

And from that sample- which was given to the French by the enemies of the Syrian government- the French were able to conclude that the sarin came from an attack ordered by President Bashir Assad himself.

Inspector Clouseau of the French Sûreté would be impressed.