I need opinions

Wow! was I a Debbie Downer last post. Sorry about that. Sometimes I vent and feel so much better after and that was one of those times. Thanks all of you that expressed concern over my marriage. I am pretty certain that all is well. Next week we will have been married 26 years and honestly for the most part I wouldn’t really change anything,,,not even the bad times. Actually, those times have helped me grow into a much more confident and self sufficient woman. While the "bad" times are happening it is hard to see the bright side but once things have settled and I can think more clearly there is always a positive. Now for the thing I need your opinion about. I have a dilemma and I think I handled it correctly but let me know what you think…. About 2 weeks ago son#3 asked if his friend *Damian (name changed but fits the kid in question) over to play. Sure I said! Damian arrives and seems a little off to me but hell, he is 12 and aren't all 12 year old boys a little off?? Anyway I was upstairs folding clothes quietly (our laundry is on the second floor…best idea I ever had, btw). We have a 2 story family room so looking out of the laundry room I can see the family room/kitchen area. So, I look out of the laundry room in time to see Damian picking up one of the kitties. (insert awww moment thinking he was going to cuddle with our little fuzzball). In a split second I see him taunting the dog with the cat. Shaking the cat at the dog. If that wasn’t bad enough, in another split second Damian throws….yes, I said THROWS the cat across the family room, launching him about 12 feet. I was absolutely horrified. When I let out a very loud "DAMIAN what did you just do"? he looks up at me and says "oh, sorry" with absolutely NO remorse. The only thing he was upset about is that he got caught. The little demon child then shrugs his shoulders and walks out the back door. Needless to say my blood was boiling by that point. I went to tell Big D and he looked at me like surely I was mistaken..sorry, no mistake, saw it with my very own eyes. At that point I called in son#3 and told him to get Damian’s things packed up (yeah, Damian thought he was coming to spend the night even though I have never met his mother nor did she call to confirm this supposed arrangement). I was so incredibly pissed that I was afraid I was going to launch HIM across the room, so I had son#2 drive him home. Again no call from mom about why her son was home again after she thought he was going to be here, even though she never called in the first place about that! I sat son#3 down and for the first time in my momming history, I told one of my kids that they were not to play with a certain individual any more and that Damian was not welcome in our home. I was blunt, and honest with son#3, told him why and why it concerned me, especially the lack of remorse. This kid scares the hell out of me…do we have an upcoming Jeffr*y Dahm*r on our hands?? He started with animal abuse too as do many serial killers and just plain old nut cases. My question is…one of my friends thinks I went too far in banning the little (monster), um child from my home. What do you think?? Be honest, I can take it if you all agree with my friend I just need to hear from people who don’t know the kid and his family as my friend does. (To make matters worse, I saw him this weekend with his family and their PUPPY..I almost went up to his mother to tell her what he did but we were in a gathering for a game (son and Damian play on the same sport team) and I didn’t think it was the right place to tell someone that her kid is frightening. Put yourself in my shoes and tell me what you would do.