Why does my 5 yr.old stepson want to turnover my 5 mths old elevated seat?

Why does stepson want to turnover my 5 mths old elevated seat?  My husband and I asked why he would do that? His reply was, and I quoate "I Dont Like her I want to Hurt Her!"  How do you take something like that?  We were totally floored and really didnt know how to react to it exccept to tell him if you ever do something like that again  you will get whipped, and then I asked him how do you not like your baby sister?  She is a part of you, and Daddy.  He looks at me with this smirk of a smile, and  eyes that are soulless and says "IM JUST AMAZING".  Wow was that a smack in the face or what?  He also is about to kicked off his school bus for hurting other kids on the bus and he also hurts kids at school.  I Have a daycare in my home and he is always hurting the kids that cannot or wont defend themselves, plus the kids that will defend themselves. Pretty much all of them!  He knows what he is doing cause he will ask them to not tell on him(which I have heard him say)and then try to lie to me with a lie that is so far out on left-field that Im like WHAT?  He has this crazy and I mean CRAZY obsession with the alphabet, I mean it is so bad that his father saw a movie title that read The Alphabet Killer and said that will be Austin someday(this was said before  had tried to hurt our daughter) . Thats not funny now and I want to know if something might be wrong with him, I am really scared for my baby girl.  He is a very very very bright little boy.  Almost to the point that sometimes I feel like he sits back and laughs about how stupid we are.  It is like he is on a mission with everything he doing, saying, seeing, feeling, and thinking that it truly scares me.  His Egg Donor(is what we like to call her) has not been in the picture since he was 2 1/2 and alot of bad things happened to my stepson while he was with Egg D when my husband and her was in thier on again off again marriage.  I have a 13 Yr old also from a previous marriage and she is lacking my attention due to the fact we have to keep the baby in our arms 24/7.  She loves the baby so much right now that Im afraid that she will end up resenting the baby, or me...etc.  He is scheduled with the school child psychologist but is that going to be enough?  Please HELP ME find a way to help this child and help my family!!!!

[whirlygirl820]

What does turn over an elevated seat mean?  Your step son sounds like he has been badly traumatized and is screaming for attention.  

[RockRose]

Your son sounds like he has reactive attachment disorder,  from not having bonding when he was a baby.

At least his blunt honesty is refreshing - few kids just flat out own up to why they do mea things.  At least with him it's quite clear that this wasn't a pure impulse.   He's honest that he wants to hurt other children.

Look up RAD.  The worst part of all this is it's virtually impossible to "cure".  

Best wishes.  This is very hard.