This is such a difficult situation. I have a great deal of empathy with the OP because my youngest son is somewhat similar in profile, although because his mental health issues are so obvious, he presents primarily as vulnerable. It may be that OP's son is equally vulnerable, but this is masked by his high level of achievement e.g. attending university, completing formal education and so on.
I will not go into my son's difficulties in detail (this is not my thread), but I will say that in our case, the behavioural difficulties come from extreme anxiety and an obsessive need to control the environment and everyone in it (at the moment, that is just me).
We have contacted the police in the past and they have come round to talk to my son. This has been helpful and it has given us a certain degree of reassurance because we know the situation is known to the authorities. We have never pressed charges. A criminal record would not be helpful to our son.
Currently, my son and I are working with CMHT and housing agencies to try to find him some supported accommodation, because as I become older, I am sure my son's control will become more vigorous as my health and stability become less predictable.
OP, I would advise a talk to the police. I do not think cutting off your son, changing locks etc should be actioned unless it is established that your son has somewhere else to go and other networks of support. He is only 20.
That said, the physical abuse and destruction of property should be a cause for the police to be informed.
I am sorry if this is not a helpful post, but my son was so explosive at 20. He is 25 now and his mental health has completely collapsed. I was just wondering if the OP's son's behaviour masked serious mental health issues.