Where a person is charged with drug possession for personal use and where the person's record is clean (for the most part), then the person can take advantage of the DEJ program to erase the conviction. Sometimes drugs are found after a DUI stop and certain courts believe that the DEJ option is not available where a non drug offense is charged along side the qualifying drug offense.
Recently, the courts have decided People v.OROZCO, Case No. G045124 holding that where the DUI is alcohol only, then the accompanying drug charge will qualify for DEJ dismissal. This is a critically beneficial decision because it can erase felony drug convictions that often require mandatory drug registration for many years.