Morality in it of itself is a biological construct.We have evolved in a way that we can perceive morality.However, objectively speaking morality does not exist as nothing justifies it.Anything that is subjective cannot be treated as objective, here is an example, other alien life forms might think that killing is right while we think it's wrong.This further prove my point.
Yes, mass murder is wrong. Any murder, whether perpetrated by a person or a government, is a direct affront to the natural order. Nobody should be allowed to murder another person without proper punishment. Without this punishment, more people may be empowered to commit acts of violent crime against others.
By definition murder is wrong. Accordingly, mass murder is also wrong. There are plenty of times when killing another human being or a number of human beings is justified. An example of a justified killing is when a soldier of security guard kills a person that is killing or attempting to kill other innocent humans.
I don't think there is any reason a person could sit back and condone mass murder. It doesn't matter the details. Mass murder is wrong and should never happen. These are the types of things that have advanced our society in the world - we are killing groups of people!
Mass murdering is wrong. There is no way to justify killing people unless it is in self defense, and to kill so many people could not be in self defense. Further support of this is that the burial was hidden and kept secret and must not have been an acknowledged act of war.