There are lots of good lawyers that specialize in this and I hope you can find one to help you. I recommend you use the find lawyer tab above to locate an attorney in your area. Many attorneys offer free consultations where you can get an idea of your legal rights. Good Luck.
Nothing herein is intended to create an attorney client relationship and the response is intended to provide generally a broad response to the area posed by the question. Each question is governed by unique facts and no answer provided is intended to specifically answer the question, but is a general overview of the area of law contained in the question.
Sorry to hear about your difficulties.
As to the POA -- your brother would have to provide it to you and under the circumstances you describe -- that is unlikely to happen.
Other options are a temporary conservatorship or a conservatorship under the Lanterman-Petris-Short Act (LPS Act).
A temporary conservatorship is appropriate when immediate action is necessary to ensure that the proposed conservatee -- your brother -- is safe until you file and go through a general conservatorship. Please note in order to qualify, the situation has to be an emergency.
Under the LPS Act, when the person is a threat to himself and others, the person may be involuntarily detained for at least 72 hours for evaluation. He can either agree to be treated -- or if it is determined that he is in need of treatment and care, an LPS conservator may be appointed
Please note that the LPS conservatorship is a 1-year conservatorship that terminates & must be renewed each year.
It is recommended that you consult with an attorney for assistance in evaluating what is the best option for your brother.
AVVO has attorney referrals in your area or you may contact the Los Angeles County Bar Association for assistance.