I'm another RA who has been to jail a few times. My last stint was county jail for a month then a diversion center...in custody, but had to get a job and pay rent while I was locked up. Someone was complaining, one day, and "sarge" (head of security) said "we don't WANT you to like it here, we WANT you to do what you need to get out and never do anything to get BACK here.
I also know someone who got locked up for not paying child support, and in GA you also lose your driver's license. It didn't phase him...he's still out doing the same stuff he was.
I would listen to your sister and give HER your support. If she's the one that is going to look like the "bad guy" for doing what's best for him and your family (hoping she doesn't bail him out) it sounds like SHE needs the support..not him.
He got where he is from his own actions. My first time in jail, nor the 2nd or 3rd, etc. gave me my wake up call, but when I relapsed and realized I could be going to prison (I was on probation), THAT was my wake up call. I had to have a lot of consequences, and they finally got too much and I said "I can't do this any more". That was over 4 years ago, and I needed every single minute I spent in jails/diversion center to get here.
Hugs and prayers,
Amy