All these descriptions are reminding me of a co-worker of mine from years ago. I describe the guy as a sociopath, he was awful to me while ever he regarded me as a threat to him professionally.
But reading these posts - I remember how he was with animals. We worked with animals in our job, plus he brought in for adoption one day, a rabbit he and his wife had kept for a couple of years. It was actually a littermate of my own pet rabbit who was a lovely-natured creature. He complained tat this rabbit would attack him and bite; I observed him with it. As he moved his hand near the rabbit (over her head) she would definitely attack him. But his hand was often above her head like this and for a rabbit, it can be a threatening position. He would also react, ALWAYS, by smacking the rabbit hard around the muzzle. I told him to leave her alone for the day and let me work with her; he was giving her away anyway, so she may as well begin to get used to different handlers.
Over the day I began moving my hand slowly, and now (his hand movements, especially when smacking her, were rapid). At first she attacked me but when I simply stopped moving my hand at all, she stopped biting me. She was only attacking out of the fear of violence; once she realised (and she learned fast) that I was not gonig to stop trying to pat her but also was not gonig to hit her, she stopped attacking me and by lunchtime she wasallowing me to pat her contentedly. The bloke's wife was also able to pat her - but when my co-worker came ner, he was unable to control his own fear and loathing and she went back to biting again (especially him).
Over the day I had to stop him from hitting her or slamming his fist against her cage; he was frustrated and angry and I had often seen him take it out against the animals. His wife later told me that he used to get a lot of fun tormenting the rabbit; instead of removing her form her cage when cleaning it, he would turn the hose on hard and hose out the rabbit hutch with the rabbit still in it. And when she got agitated, he would then hit her.
No flamin' wonder!
So be aware - this is what such a child can turn into. I know enough about my co-worker's past to know he undoubtedly had Reactive Attachment Disorder (RAD) as well as PTSD. I've since known another man with similar background - also similarly a bit weird and certainly not someone I could ever trust, even though he considers me a friend. I'm friendly to him, but I can't consider him MY friend.
In the meantime - keep the animals safe. Removing them is not only precaution, it is consequence.
Such a difficult situation for you, not knowing which way to turn.
Marg