This all started a year ago. I found my little sister crying in the bathroom with the door locked. After trying to find out what had happened I eventually got her to talk to me and tell me that my brother had grabbed her and groped her. She was f---ing 11. He's 13 and should definitely have known better. Well long story short he goes to "therapy" (I have seen no noticeable improvement) and my parents pretty much just waste this whole thing out until it blows over. No family have been notified and this a--hole is regularly in contact with children in the family, as the parents do not know what has happened. Now this is added on to the number of violent things he has always done. He screams, cusses, and is violent all in a household that is normally quite timid. We do not curse and he constantly drops F bombs in front of my parents. After finding out somethings today I am done. He has spent a lot of time on my dad's laptop, and he is an idiot that doesn't know the existence of web history so I peaked to see what he's been up to. Turns out he's been looking to make homemade weapons and explosives. I have yet to confront my parents with this knowledge, but up until this point all he's gotten are slaps on the wrist. Now even this may seem harmless, but he's acted things like this out in the past. He and his friends have lit things on fire, spray painted and egged our house (I don't know either), and made spears with kitchen knives and sticks (they through them at each other). This is not a safe household anymore, and if anything I want to make sure my sister is safe, and that no one else gets hurt. There are always warning signs to terrorist acts (Boston Bombings, Oklahoma bombings, every shooting, etc.) so how do I deal with this.
thanks guys.