General question about the possibility of objective moral truth

[Wyrd of Gawd]

Hello to everyone

I have a general question about moral: The discussion between religious people and atheists often turns around the question if someone needs to be believer in order to follow moral rules.
In my opinion an atheist can be as much a person of high moral standards as a religious person (and some atheists can even have a higher moral standard than some religious people). Just to say that right at the beginning.

Now I would like to ask: Is from an atheistic point of view a moral conviction like "killing of people is morally wrong" an objective fact? Or is it a social convention, which means it is a subjective view?

Thanks for any answers!

As long as you are the one doing the killing and not the dying you're good to go.  Cops get away with murder everyday when they kill someone for some silly reason.  The system loves them.  So it must not be wrong for them to do that even in States that don't have the death penalty for crimes.