If convicted of a VC 23153, then it is possible to get the charged reduced from a felony to a misdemeanor. Are they serving time in prison, or county jail? Note that in order to get the charge reduced to a misdemeanor and expunged, he would need to have successfully completed the probation for this offense amongst other factors.
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One note in addition to the prior correct responses. The offense that your family member has been convicted of, assuming the enhancement of GBI was indeed plead to, is a "Serious" offense under the Three Strikes Law. In other words, your family member has a Strike conviction on his record. Not all attorneys are aware that this offense is a Strike offense. While the law generally states that if a petition for reduction to misdemeanor is granted, the conviction becomes a "misdemeanor for all purposes", there is one exception... Even if in the future the charge is reduced to a misdemeanor, your family member will still have a Strike conviction on his record for the purposes of sentencing in future cases. This matters if your family member is ever charged in the future with another felony case.