Your uncle needs a lawyer from the Sacramento area. There is n way of knowing whether he will be deported as not enough information has been provided. I will change your practice area to immigration so that the immigration lawyers will be able to answer.
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Can't tell from the little you have shared - we don't even know what his status in this country is. If there were endangerment/aggravated issues or a repeat offense, any possible immigration consequences would be much more serious. If it is a simple DUI and he has a green card, probably not so bad. If undocumented, he can end up in removal proceedings. Contact an immigration attorney ASAP.
Gunda J. Brost Brost Law Office This advice does not form an attorney-client relationship and is merely informative. It should not by itself be relied upon to address a legal concern.