The Fit Hit the Shan

Well, it really did. Disturbed by screams about 6:00 tonight, came inside to find the oldest boy had the oldest girl on the floor and was wailing on her. Now to my mind, there is not now, never has been, and never will be, an excuse to hit a girl. Ever. Sure I got in arguments and scraps with my little sis, but there was always a line, and you never crossed it.
But to see this, this big fifteen year old holding down this screaming girl, I saw red. The last couple of weeks he has been getting more abusive and stroppy, and this was the final straw. I haven't lost the plot like that since the days of my brother abusing my mum.
I grabbed him and hauled him off her shouting something incoherent at him. She was off and running out the door, the littlest boy was cowering in the corner and he came off the sofa calling me for everything under the sun. He shouted that he would take me down, so I put him back down into that sofa again, scooped up the little one and beata retreat. He was screaming in rage,something about me being such a big man, taking on a fifteen year old, I was a fucking coward yadda yadda yadda. Hey I've never struck a woman, and the only two fights I've ever been in was when I was protecting someone who couldn't protect themselves. But be that as it may, me and the little guy beat a retreat to my sleepout and left him alone to lock himself in the house and rant and vent. Mum comes home about and hour later and he starts winding up to lay into her, but this time he grabs a knife. So I called the cops, while his mother managed to get the knife off him. They showed up about twenty minutes later,and meantime he was barricaded in his bedroom rant and raging how we didn't have the balls to call the cops on him. End of the day kid, I never hurt no ladies. The cops took him away to spend the night with a family friend, and more I am sure will follow tomorrow. Meantime,my dramas aren't over. Following my run in with him,I get a phone call from my mum telling me my sixteen year old nephew/surrogate son has pulled himself out of school after being caught smoking weed with some cretins during lunch break. And she tells me he has threatened to hurt her too. What the fuck? Here is a kid that made great strides this year getting himself set up for success, and now he is throwing it all away for what?
Seriously?
What the fuck is goingon?