The only way you can be sure that there is one 'true morality is, "If you don't want it done to you then don't do it to others."
if I kill someone's loved one for some reason maybe for me it is not morally wrong because that person "deserved it" but if they kill someone dear to me can I consider it morally acceptable? definitely not
I know, I understand that but it's important to talk about it, it's the only way we can understand and be understood and protect ourselves from misunderstandings.