Just because you bailed your brother out does not mean that he will not be facing jail time. Many times family members mistakenly believe that they are bringing criminal charges against someone, or that they have the power to refuse to prosecute & the charges will miraculously disappear. In the case you described, it sounds as though your brother will have criminal charges filed against him by the State of Arizona. If anything, you may be a witness - but you are not in control of these charges that will likely result in a trial.

When your brother goes to trial, he will face the drug charges. Meth is a serious problem in Arizona, so I'm not sure how the prosecutor will handle this if he is found guilty. A lot of that is based upon his criminal record.  If he has prior convictions for the above, it likely will not be used against him since he is a juvenile - but it may be a factor in sentencing him. In any case, your brother may go to jail without any say by you or your mom.

If you want to take it a step further you or your mother could get an order of protection against your brother. This would mean that he would not be allowed within a certain distance of you, and would involve him not returning to the home your mother owns &/or resides in. This may not be as much of a goal given your brother's violent tendencies, however, it would control more than just getting him out of the house - it would also control any and all contact between your brother and you and your family.