I think it is possible to:
-immense sympathy for the victims
-revulsion at the criminals
-sorrow at the fact that the criminals have turned out how they have
and at the same time want to understand the underlying causation for what they did (again -for the hard of thinking - this is not to excuse them). This would be with a view to, hopefully, stopping others turning out the same way. I do happen to think that, sometimes, the answer will simply be 'they were evil' but humans are usually more complex than that.
None of these contradict any of the others.
Unfortunately these not particularly complicated ideas are beyond some people's critical thinking powers, which is why you always get a handful of nitwits, frothing at the mouth and accusing anyone attempting any kind of analysis of excusing the criminal.
And yes, all of the above equally applies to rapists, child abusers, you name it
But the fact is that that doesn't tend to happen on MN when it comes to abusive men. Women in abusive relationships almost always get advised to leave, not to try to understand their partners and support them to change their behaviour. I've read threads about Ian Brady and John Worboys, and the sympathy was definitely aimed at the victims, not the perpetrators. I'm usually the least "what about teh menz?" person in the world, but I find the double standards on MN regarding this issue utterly bizarre. I think some people just don't want to admit that some mothers don't care about their children and may actively want to harm them.