Not taking the bus due to psychiatric illness does not eliminate all means of complying with the court order.
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It is unclear why the person would be completely unable to attend AA. Is it possible for someone to drive him? Is there AA within walking or biking distance? These are some of the first questions that will have to be addressed. To seek relief from a court order usually you must exhaust every possible remedy first.
These statements do not constitute legal advice. They are meant to be general in nature, for any specific legal questions you should always seek the counsel of an experienced attorney.
First, the judge will likely want to know whether the client/defendant is taking his prescribed medications so that client will not feel in danger just riding the bus or be a likely threat to others. I wouldn't be surprised if there's also a condition of probation to continue and maintain any mental health treatment-- is client/defendant doing that? And how is client getting to those meetings? The judge will realize there are other ways to get places other than by bus, for example friends, family, bike riding (you are in Santa Barbara after all), taxi cabs--- in fact all that gas money that is being saved since client can't drive anymore-- can pay for a few cab rides....perhaps one solution is to offer something other than AA--- in many communities there a "Dual Diagnosis" programs that offer mental health and alcohol treatment together --- since self medicating with alcohol is not unusual for folks with mental health issues. That program could be more effective than AA and it may be more convenient to get to... maybe.