Missouri recently expanded the expungment statute, RSMO 610.140, allowing for more expungements of misdemeanor and felony convictions if the petitioner and prior conviction meets certain criteria. Under the law, a Felony (not involving sex crimes or act of violence) can be expunged after seven years from date of completion of probation or jail term. The Petitioner must have a clean record since the completion date of the offense. The law allows the expungment of up to two misdemeanors that involved jail time after waiting three years from date of completion of probation. Again, the petitioner must have a clean record during the three "wait" period. The law allows unlimited expungments of misdemeanors that did NOT involve jail time. Prime examples are traffic tickets and possession of marijuana/paraphernalia charges. The three year wait time applies as well. I would suggest getting any misdemeanor drug conviction expunged as soon as eligible. Once expunged, you do NOT have to report the arrest and/or conviction to any employer or school. The expunged record is "wiped clean" and allows the petitioner to reclaim her status prior to getting the charge or ticket.
However, DWI convictions require a 10-year wait period from the date of the Guilty plea in court. The petitioner must file for expungment in the court where he was initially sentenced. The court will certainly look at the petitioner's record during probation and since the completion of probation or parole. Only one prior misdemeanor DWI conviction or suspended sentence (SIS or SES) can be expunged. A CDL (commercial license) holder can not be granted an expungment under any circumstances. The intent of the expungment is to restore the individual to the status they held prior to the arrest or charge. The expunged conviction can not be used against the petitioner except under limited circumstances. Generally, law enforcement has access to the expunged files but non-law enforcement agencies should not have access to such files.