Oh, details, details, we never look for them when deciding to give three young children to a psychopath ran family
You seem to be imagining a scenario where there was a dispute over custody where a court was involved, and that the court, knowing that the mother would move in with a psychopathic criminal, handed custody over to her.
I'm not sure what article you read, but the one linked mentions none of that, so I'll assume that this is a figment of a very bitter mind.