HorridHenryrule, you are right about who gets the blame.
I took full responsibility for trying to understand and correct DS behaviour in a way that I hoped would not send him down the same path as his useless biological parent.
No one (OP, OPs DH, and either DS) should ever have to deal with attempted or actual violence and I don't for one minute condone OPs DS2 behaviour or place the blame at OPs DHs feet. My point regarding OPs DH was that his current interaction feeds into her DS2's thinking that you can solve your issues with threats/ violence and that really doesn't help anyone.
The root cause of DS2's behaviour needs to be identified and addressed not just the behaviour that happens as a result of his feelings.
I completely agree with posters who say OPs DS2 needs to take responsibility for his actions but doesn't a parent taking responsibility for helping to identify why their DC might be acting in such a way go hand in hand?
Aggressive behaviour is learned behaviour, as is taking responsibility for your actions.
OPs DS2 will not disappear into another universe if she calls the police or social services or throws him out to extended family to 'deal' with instead. Surely the problem then just becomes someone else/ society's problem?
I agreed with Maryz's view on SS but it was really interesting to hear from bigmac4me that although temporary placements do happen often, sadly the majority do not work as it often just becomes a pattern for the child. That is in no way SS/ Foster Carers fault but probably the child's feelings of resentment adding to whatever negative feelings already existed before such a placement.
OP DS2 needs a solution that takes the confrontation out of the situation immediately and forces him to recognise how destructive his behaviour is.
Often we class the words exchanged in the heat of the moment as addressing/speaking to our children about their bad behaviour. But in my experience it is having the continued conversations before situations occur that has been the biggest help for DS to understand and influence his decisions/actions.
OP - your DS needs to hear that you love him but dislike some of his behaviour/ decisions. Deciding to talk to him to try and find out what is causing his behaviour is not condoning his actions or preventing him from taking responsibility for those actions.
Quite the opposite, I think. Part of taking responsibility for ones actions means understanding why you behaved in that way so you can take steps to prevent it happening again. He is still quite young and may not even really understand himself why he is so angry without a calm constructive conversation.
As identified by Fairyflaps, I found low confidence to be one of the main sources of frustration that had been left unaddressed and was then was also able to talk to DS about how to improve his confidence.
Only through calm communication are you likely to reach a breakthrough.
Up until now, your DS2s way of dealing with his frustration is to lash out. When talking to him about this, include DH, addressing underlying feelings and alternative ways of dealing with anger.
What possible benefit can be achieved by labelling DS2 the bad guy?
A child who feels negatively about themselves will rarely project positivity to those around them, especially those closest.
Rather than telling him he is bad, refer to the bad decisions he is currently making and how he can and must change those into positive decisions.
Even those deemed 'good people' have done bad things or made bad decisions in their past.
Apologies for the long ramble. I certainly do not have all the answers but hope that anything in any of the posts on here can help you turn this situation around for everyone in your household. You all deserve to feel loved and safe within your family unit. 