I’d bet good money against a bent paperclip that they had childhood trauma already. That doesn’t excuse what they’ve done, in fact that makes it worse. It’s likely the thought was “this is what happened to me to make me the person I am today” or similar.
That being said, once you do this to a child you’re no longer a person in my eyes either. They aren’t human. They aren’t animals. They are nothing. The whole reason I’m not in charge of anything is because I think we should throw them in an oubliette and let them survive by drinking from puddles and eating rats. That’s not justice, that’s revenge. I just don’t have anything else in my heart for these people.