One of my philosophy professors put it to me this way, "Is killing an infant just for fun ever morally ambiguous?" I feel like there are moral absolutes, but only if we get specific like that. Killing is obviously morally permissible for a lot of people, particularly in self-defense. However, I've yet to meet someone who says killing an infant just for the fun of it is okay.
There are rumors of child snuff porn on the dark net, if true it would appear that some people find it entertaining. And before anyone asks I am not going to investigate to find out if it's true.
But is that morally right? Would they even say that? Or would those people be sociopaths and have no barometer for right or wrong?