The Commonwealth must prove through a certified copy that you are a subsequent offender. A good OUI lawyer will make the Commonwealth come up with the certified record of conviction because if they cannot then they are unable to prove that it truly is a subsequent offense. It is important to note that the Registry of Motor Vehicles (RMV) does not have these same strict conditions of proof and may impose a license suspension as a subsequent offender even though a good OUI lawyer has been able to have the case resolved as a lesser offense.
Speak with an experienced Boston criminal lawyer now to get free advice, it is important to know where you stand while the case is pending. Just being charged and/or refusing the breathalyzer carry a license suspension which you need to be aware of.