Who was the first person killed with a gun?

Although firearms of sorts were used in China first ,it was the Europeans who saw the potential of this weapon. No records exist of a China man being killed with a gun before that of a European.

In 1415 King Henry V was marching an army of 5,000 men through France when a huge force of 30,000 french soldiers ,mostly knights appeared. The battle of Agincourt took place which was part of the Hundred Years War. This battle was won by the English Long Bow. Although out numbered 6 to 1 the English massacred their French foes. After the battle stories were told and corpses were inspected and it seems that at least 1 French soldier had a gun and had killed an English soldier.

So in conclusion the first person killed with a gun was an unknown English soldier in 1415.