RAD-Biological Son

I have been reading through the RAD of adoptive children and so much of what is said, I can relate to my 3 year old, biological son. I read a post on here asking is it possible for a child to have RAD if he has good parents and comes from a good home and I suppose that's my question as well. Though, my story is a bit different than theirs.My son was born in 2012, When he was about 2 weeks old I had left him with a baby sitter, it was a girl that I've known my entire life, throughout grade school, middle school, high school, and the start of our adult lives, I knew her pretty well. She offered to watch him, so that I could go out and spend time with my friends, see, I already had two other children, at the time a 1 and 3 year old and during those three years, I hadn't gone out with friends or done anything away from my kids, they were my entire world, I wrapped myself up in them. It turns out that my so called friend and baby sitter left my children with her mother in law, who was a certified, registered nurse instead of watching my 1 year old and 2 week old herself. The next morning, she brought my children back and my 2 week old was crying, I nursed him and thought he may have been having a bad reaction to the formula, so I cuddled him and did my best to comfort him. I asked her if he had been this way all night and she stated that he had just started crying. After a week, I started to notice that one leg was bigger than the other leg, we had a few others hold him during this time, and they never noticed his leg either, as well as change his diaper. I immediately took him to the hospital to figure out what was wrong, he hadn't cried all week so I couldn't imagine what I'd find out. It turned out his leg was broken. Someone had twisted several times, and it was broken. Since he was a new born his bones were still cartilage so it takes a lot to break a babies bone. They took my children for 2 months from me, my oldest son was left off the case and given to his father, but his father was advised not to allow me to see him. My baby and my 1 year old was given to my aunt. This was the worst time ever, and so traumatic for myself and my husband and our children.Later, we came to find out that the nurse, broke his leg, she said that she fell with him and it hit the table, but she failed a lie detector test. She stated that she had taken a lot of medication and was walking in the dark with him and hit a table and fell with him. She said that she told my "friend" to tell us this when she dropped my children off to me. Needless to say, she was never charged, she was marked down as the abuser, however.After that we received our children back, trying to mend what was broken, my 1 year old was so traumatized that he would scream if he thought I was getting out of the car, he would scream until I went to the back and opened the door and had him in my arms. Anytime someone would come into my house he would freak out and run to me or his father, just so they wouldn't take him. My oldest son, I got back weeks before, because I obtained a lawyer and since he wasn't in the paper work, they couldn't keep him from me legally.So, now we have all the story that leads up to this moment, however, during this time, my baby was put in to our local hospital, transferred from there to a bigger hospital, with multiple nurses taking care of him, and then had foster parents come in to look after him. After a few days, my aunt came to the hospital picked him up and he lived with her the remainder of the time. Then he was taken from her and given back to us. This shows that he changed care givers and maybe lost faith and trust in those who are supposed to form a bond with him. I'm not sure what happened. But, he has every single sign of RAD. I have done my best to make things better. For a year after we got them back we were on family preservation to help build our family back together, since it was torn to pieces. There wasn't much they could do for a baby though, he was about 3 months old, he couldn't talk, he couldn't say how he felt.So, I did everything I could to bond with him, treated him as I would any one of my other children, though I was more careful with him because he seemed to be fragile after having a broken leg at his age. When we got him back he would cry for hours on in and it seemed that he was impossible to soothe at times, I still seen no indication that something may be wrong with him. I would spend time with him, feed him baby food, and do my best to love on him. When he was about 9-11 months old he started eating his own poop, I asked his doctor what could this be, why would he be doing such a thing and she told me not to worry about it. He didn't seem to be attached emotionally or show any emotions, usually babies are happy to see their parents. When he hit age 1 he was wiping poop every where, all over the walls, and toys and his bed, I would have to clean it daily. It got to the point that I felt like he was doing it on purpose, but how can a 1 year old be doing something to hurt me, on purpose? And this was just the beginning of me thinking, I was insane.What he does/did:*Wiped poop on the walls and bed and toys*Robs the kitchen at night/early morning when he thinks we're all asleep*Steals the other kids food even though he had more than they did on their plates*Tears paint off the walls*Tears up any/every toy he gets his hands on*Stares at me hours on in glaring*Never shows any emotions *Wouldn't speak to adults,but he could speak because we could hear him speaking to his siblings, clearly too*Manipulates, he will act normal around others and talk to me, and say he loves me, and be an angel, people will think I'm lying and that he really doesn't act like this.*He's bit me a few times, kicked me, hit me*He's always in trouble, it's like I'm constantly in a fight with him.*He would not potty train, he could however, put his own diaper on and change his own diaper but would refuse to potty train*He will hit the other kids and pick on them but as soon as they do it to him he squeals and freaks out*He has stolen my babies bottle even though he hasn't had one in years*He one time stole an entire birthday cake and ate it*He will try to get his siblings in trouble by doing random things and saying they did it*He won't play with the other kids, he will just stand/sit there and stare as they play and glare at them, even when told to go play.*He will fall out and hit his head on purpose and then cry*He has made himself bleed from falling out*He used to jump out of his crib and hurt himself , so we took it away*He tore up 6 toddler mattresses, tore them to pieces*He would force himself to throw up when ever he had anything sweet just to taste it again*He can't get enough food, he will eat and eat and eat until it makes him sick*He will take the other kids food, even when he's been fed more than his share*He can do the same thing over and over and over and gets in trouble and does not seem to learn from his past behaviors.*We had to put a gate up in his room so he wouldn't get out at night and steal things.*He has gotten in the tub, fully clothed, and turned the water on, without us knowing, when he was supposed to be in bed asleep.*He has snuck out of my aunts house, unlocked the dead bolt and everything, and was found on the porch staring down at the steps in the middle of the night at like 1am.He's done a lot and there are many more things he has done, but it would take forever to list. I thought I was crazy because I'd tell people what he does and they'd act like a child couldn't do that, a child couldn't be that bad and they'd always say "well, he doesn't know what he's doing." In fact, he didn't treat his father the way he did me for the longest, not until his father realized he was manipulating him, as soon as he figured it out, my son, started throwing shoes at him, and glaring at him as well. So, my aunt and I are pretty close, she's the one who had the boys when they were taken and I'd tell her how awful he is and how he treats me. We finally moved up near her because of better schools and what not. She would get so upset with me telling her how he is, that she just would ignore me at some point. The first day she came to our house, she didn't see the same little boy that I described, in fact she told me he seemed very respectful. So, I did what any good mother would do and allowed her to keep him for a few days. Those few days, he sat on the couch and wouldn't move unless she told him to, he even one time looked at her, and pooped while looking at her, because she had just told him if he has to poop let her know. He wouldn't play with toys or her kids, nothing, she had the hardest time and apologized because she didn't believe me. She couldn't believe a 3 year old could be this bad.So, my question is, is it possible that we could still be doing everything right, but because of his broken leg and his time being away from us and going through multiple care givers during that time, caused him to have RAD?