How will my criminal record affect a prosecutor’s charging decision? What if my past record has been expunged or sealed?
Even when intake prosecutors conduct no other investigation, they almost always check to see whether an accused has a criminal record (called a rap sheet, or "priors"). A past criminal record, even for a different crime, makes it more likely that charges will be filed, and may affect the severity of those charges.
For example, a shoplifting charge against a defendant with a prior shoplifting conviction may be filed as a felony instead of a misdemeanor petty theft (where the laws support that type of escalation, that's called "petty with a prior"). Similarly, a charge of drunk driving with a prior always carries a more severe penalty than a first charge of drunk driving.
Defendants who have sealed, expunged, or dismissed a prior conviction cannot count on the fact of the conviction not coming to light when a prosecutor looks for evidence of past criminal convictions. Sealing a record is most effective in the civil sphere, where you will usually be entitled to say, "No" when asked by an employer about whether you have a criminal record.
by: Sara J. Berman