Killing an animal is serious. I don't want to scare you, but it's a huge red flag for big problems. Is there anyway you can get him evaluated by a panel of experts, like we do in the US? My son is on the autism spectrum and no way would he hurt anything or weld a knife. ODD, Learning Disability (LD) and autism, in my opinion, wouldn't explain the extreme violence from such a young kid. I'd want this child tested more intensively and for psychiatric on top of neurological issues. And if anyone recommends an ADHD stimulant, I'd think twice. For a child who is violent, more is probably going on than that and stims can make violent kids even worse. I bring that up because stims seem the first line of medications use in many countries, even if the child is raging out of control and hurting people, and I don't understand it--there are better medications. Any mood disorders or substance abuse on the family tree? I can tell you one thing. No matter what kind of guilt trip a behavioral therapist (I don't care for them) wants to lay on you, this type of behavior is way over-the-top of normal and has not ONE thing to do with your parenting skills and is not your fault. Don't let anyone tell you it does. He is sick and needs treatment. It's not his fault either. (((Hugs)))