How should I react when my bro comes home from jail? when i found out, I showed concern?

my bro called last night to the basement. He is 26 and will be 27 in december. I am 21 still living at home with my parents. Anyway, I get a weird automated message that the following fone call from the prison will be recorded and i was a little freaked out because, i have never heard anything like that before never being involved with jail. Anyway, my bro said he was in jail so I asked, 'are you ok? what happened.' and I ran upstairs and told my dad he needed to get my bro out of jail. My dad told me my bro got in a fight with his girlfriend and the neighbors called the cops on him. I don't know what happened and my dad said stacy may have said he put his hands on her, but idk. he has got physical with me when he got mad but it was only once and i don't think he did that to her. My dad asked if he was drunk when they fought and he said no. I wish he would stop that drinking and smoking he does. They live in a studio apartment and he does not work. my dad posted his bail. what to say?