Alateen is for kids, but Al-Anon is for “friends and family of problem drinkers.” If it helps, that’s great.
Well it would be nice to have dad’s support, right?
I’m sure your brother feels like shit about his problem, no?
I third Al-Anon. It’s really a wonderful program, and it teaches you how to be supportive of the alcoholic without miring yourself in his bullshit. If you don’t feel comfortable going to face-to-face meetings, there are meetings available online and by telephone.
Ultimately, the OP’s brother is going to have to make his own decisions about what he wants to do. The ideal is, of course, sobriety, but whether he continues to drink is his own choice. It sucks, but there it is.
Did you read this bit in post #18?
What on earth can dad, or anyone else do, to “support” the brother? He’s already in a better position to get care and treatment than most people.
It’s quite likely that brother does feel like shit. I don’t think anyone here (certainly not the OP, not me) is devoid of sympathy for him. He’s an addict, he’s sick. But nobody else can help him unless he wants to be helped. Nobody else is responsible for his alcoholism, and nobody else can cure him of it.
I think Al-Anon is a great idea, too - you and your brother and your family have had this dance going on for a long time now, and it would probably really help you to get some outside opinions on what is best for you and for him. You might be doing things that actually hurt him when you’re trying to help him. This is hard on you, too, I_Know_Nothing - instead of a good brother, you got a bad drunk. It really helps to talk to people going through the same things, and know that you’re not alone.
Just as an FIY - in Al-Anon (like AA) meetings nobody will offer opinions or advice on a specific person’s situation; and that won’t really be permitted by the facilitator. The dynamic is more about sharing and learning from others’ stories, a sense of fellowship, and so on.
Of course there’s no rule about making friends and sharing advice or opinions outside of the meetings. 
The next thing the police say, Left Hand of Dorkness, is that you have to let the person back in. That’s why I_Know_Nothing my suggestion is that you move out. Much easier and without the legal entanglements. And having you there may make him feel safe enough to over-indulge. I doubt the other tenents will cut him the slack you do and subsequent consequences might knock the starch out of his sails (affect his sense of entitlement.) From what you’ve said you love your brother and you all share a bond when he’s not in the belly of the beast. Love him enough to leave, but let him know you’ll be there when it gets really tough as he tries to work things out. Al-Anon is a great idea. And they don’t talk about the resident drunk so much as lead you into looking at yourself, where your main concern should be.
I think it’s obvious that if you want any chance at peace for yourself, OP, you’ll have to move out. You can’t make him stop drinking or make any other choices for himself, but you can make your own choices about the situation. If you knew that he was an alcoholic before you moved in, then I’d say you made a very bad decision. But cut your losses and get out- that doesn’t mean you have to stop loving him and being his brother, it just means that you’re looking out for yourself, and that’s okay.
I live in Warwick, and there is a bar I pass on days I drive the kids to school. There are always cars there at 850ish in the morning.
It sounds harsh, and “support” is a pretty broad word, but we’re not disowning him. I know he knows I will never stop caring(he told me a few times years ago that he wouldn’t be alive if it wasn’t for me, which I’m sure is not exactly true, just a little overdramatic) and I’m almost as sure he knows that about my dad and stepmom. But the countless peptalks, reassuring, rides, food, financial planning help(not giving him money), trying to make non drinking plans too keep him away from the bars, etc has zero affect on him. He blatantly refuses anything that would help his situation; and so willfully and purposefully does everything to make things worse.
The perfect illustration of the second part is when he was going to his Intensive Outpatient program(IOP). He wanted me to drive him to a bar one night. I brought up the point that he gets majorly depressed when and after he drinks. He says its alright because he has the IOP the next day. So he wanted to use the emotional support he’d get from the 4 hour IOP session to get over the fit of depression he knows he’ll have from getting hammered the night before. Pure genius.
Funny story:)We went through this same stuff for years in Dallas where we grew up. He ends up in Chicago after some failed attempts at rehab when a friend of his writes a fake resume to get him a job there. Now its still stressful having a loved one that does things like, loses over $10K to some Vietnamese gangsters, or say, totals his car by driving it into a wall…on purpose; but it was quite the relief to have him so far away. He meets a girl who’s also had a tough past, FF a year he’s in a stable relationship. An absolute miracle. “Hey Devon you should move to Chicago.” No I’m trying to build a career here in Dallas, plus its still nice having him at a distance. FF a few more years…They own a house, a car, and are raising her sister’s daughter(long story). She’s been back to Dallas twice to meet the family. We all get along. We eventually decide I’ll transfer to Chicago and I’ll also be full time tutor to the daughter. I move, she splits, he goes off the deep end. The circle is now complete. (not a sob story btw, just some irony I somehow felt compelled to write down)
It’s my Friday night. I need a drink. He better not be there.