OP,
I have children that age.
This is so serious.
This is not a sibling tussle.
This is domestic violence in your home.
Your daughter has been seriously assaulted.
Your son is so dismissive and entitled, he is refusing to answer questions?
You and your husband are being incredibly passive about this.
He should have been asked to leave the house immediately so that your daughter could feel safe when she returned home.
Let him stay with a friend.
He's a big boy that feels comfortable assaulting his sister, he'll work out somewhere to stay.
Your daughter was crying all day in college and you think a firm talking to him is appropriate?
Your poor daughter.
I hope she has some friends and adults that care about her and encourage her to involve the police.
He's the makings of a thug and the fact that it is out of character is wrong, it is part of his character, you just hadn't seen it.
He assaulted her twice, once when she was outside the bathroom and then when he went back for more and wouldn't allow her to close the door.
This is so serious OP.
You have chosen him over your daughter's safety, and she will never forget this.
As she matures she will realise that her parents chose him by allowing him to stay.
The enormity of what you did will remain with her.
This is most certainly not siblings fighting in any shape or form.
This is a man assaulting a woman.
How you can put your son ahead of your daughters safety is incredibly sad.
I repeat, I hope she has people she can tell who will encourage her to go to the police and protect as you and your husband are choosing not to.
If one of my son's assaulted my daughters, I wouldn't be able to look at him with the fury I would feel.
Yours has so little respect for you he is fobbing you off and refusing to answer.
Unbelievable behaviour.
All part of the character of someone who believes they answer to no one and can do as they please.
Your poor daughter.