Is a Crime Still a Crime When it Seems Morally Correct?

In September 2008, Li Shiming was stabbed through the heart by a 19 year-old Chinese boy, Zhang Xuping. Generally, this case would be classified as morally and legally wrong; but many people have come forward to say that Li was a terrible communist official. On many accounts he was said to have taken land by force. Some 20,000 people came forward to defend the assassination of the greedy official.

My question is simple. Should this boy be pardoned for excecuting an overenforcer? One man came forward and even said "I wanted to kill Li myself, but I was too weak." In fact Zhang was hired by another farmer whos land was stolen from by Li. It is clear that this official was hated and deserved some time of punishment for his actions. But my moral compass just can't let go that Li had to die. Perhaps another method of punishment could have been taken. Yet, I also don't think that Zhang should suffer the death penalty. We will have two murders on our hands instead of just the one.