You see a rabid dog standing in the road. You're handed a hunting rifle. You take aim and kill it. You don't take pride in the killing. You did it with regret. It was just something you had to do.
You didn't do it because the dog's life had no value for you but because it represented a greater danger to other lives. You didn't regard the dog as evil. You saw it as sick.
You didn't hate the dog. If you hated anything, it was ignorance because we don't know how to cure rabies.
Now, a hypothetical: The year is 1940 and you are in Germany. You have a rifle and the perfect opportunity to kill Adolf Hitler, you know what you now know about the extent of his crimes.
How does the hypothetical for you differ from the rabid dog killing?
If you believe it's always wrong to kill, please tell us why you wouldn't take the shot.
If you would kill him with hate because you think he's evil and not sick, please explain why.
I would not kill him for 3 reasons
1) My parents met as a result of WW2, therefore if I kill him my parents never meet and resulting from that causality I might cease to exist.
2) There were many technical advances from that war, in medicine, in technology and in science. Would you be able to run this board without the computer being invented?
Colossus, the first electronic programmable computer was developed to decode enigma and other German codes.
3) Hitler was insane and as a result did not fight the war safely, had he died one of his general's or maybe Himmler or Goerring would have stepped into his shoes and not attacked Russia or would have held the Japanese back from Pearl Harbour until after Britain was done and the war might have ended very differently, had the Germans restricted their fighting to one front only. Finish Britain, leave the colonies to Japan, then gather strength move on Russia but do it properly, this time, then go for Africa and before you know it America is on its own fighting on three fronts, maybe four depending on how Mexico goes.
I think that would maybe give a very unwelcome result.
So no I would not kill him.