The rule
§ 12-1.3-2(i) provides that "[n]otwithstanding the provisions of subsections (a) through (f)" — that is, notwithstanding first-offender status and every waiting period in the section — a person may move to expunge records related to an offense that has been decriminalized after the date of their conviction. The court then holds a hearing in the court of the original conviction.
What the court must find
§ 12-1.3-3(e) sets the conditions. After a hearing at which it finds that all conditions of the original criminal sentence have been completed and that all fines, fees and costs related to the conviction have been paid in full, the court orders the expungement — and orders it "without cost to the petitioner."
So there is no waiting period, but there is still a completion requirement. Finish the sentence and clear the balance and you can file immediately.
Proving the offense was decriminalized
The same subsection provides that the court "may require the petitioner to demonstrate that the prior criminal conviction would qualify as a decriminalized offense under current law," and says the demonstration "may include, but is not limited to, an affidavit signed by the petitioner" attesting to that fact.
In other words, your own sworn statement can carry it. This is a low bar by design.
Marijuana is handled separately
Marijuana possession has its own, more generous section — § 12-1.3-5 — which makes the expungement automatic and overrides prior convictions, pending charges and unpaid fines. If that is your offense, that statute governs rather than this one.
