My stepson (16 years old, 6'5'", 250#) strangled my W (his mother) after he became angry that she woke him from a nap in the middle of the day. I saw the whole thing. He wrapped his hands around her throat, physically lifted her up off the floor and then threw her back onto the couch. My W hit her head on an end table. I screamed at stepson to get away from her and go into his room. He obeyed. W was not seriously injured although his attack did temporarily damage her vision. I wanted to call 911 and have him arrested/hospitalized immediately, my W asked me not to do so, so I did not. We called his father (with whom he lives) and his father came to pick him up. Following the incident there were several emergency therapy sessions - SS has a long history of emotional problems and anger issues, and has been in therapy off and on since the age of 10.He has a younger brother (SS#2) whom he has attacked also by the way. The little brother also witnessed this incident and had a meltdown of his own. Therapy helped to re-normalize day to day interactions however, SS never apologized or displayed one iota of remorse for his behavior. He has not tried to attack her again, however he did become violent with his father after this episode, and as a result he was hospitalized. Father did not want any consequences for this child, my W and I insisted that he be hospitalized. We also asked that he receive an evaluation for an IEP due to his emotional problems causing him to fail in school, although he is extremely intelligent. Due to all of these issues, SS blames us for "ruining his life" and has cut off all contact with us for the time being. I can still see my SS attacking my W. The experience of witnessing his assault of my spouse re-ignited a lot of early traumatic experiences from my upbringing. I am in counseling getting help for this. My issue though is that my W wants me to be open to allowing this SS back into our home. I have told my W that I would need firm conditions for that to happen, including a frank sit down discussion between myself and SS about the expectations for his behavior. At the moment it is a moot point, he hates us both and never intends to see us again, but he is just 15 years old and a child. I see so many stories and know so many people who go through this. It truly never ends in some cases. I will need to protect myself from this insanity and violence, even if it means living apart from my W at some point in the future.Witnessing his assault of my W caused me to regress somewhat, I am now re-experiencing other traumatic incidents from my own childhood. It really opened Pandora's box and I feel very strongly that I am not safe around SS, and neither is W. W has told me she has premonitions that SS will kill her one day. The sense of helplessness and hopelessness is a very familiar one. I have not come this far, at the age of nearly 50, to live in fear once again. At the same time I need to be sure I am not overreacting. At the moment there is no danger because there is no SS in the picture. But that could change at any moment and that is what I worry about.