Before states passed laws decriminalizing the possession of marijuana, thousands of people were arrested, convicted, and sentenced to jail for possession.
For many who were convicted for marijuana possessions, their crime is no longer a crime under new state laws, which allow adults to possess a small amount of marijuana. However, those already convicted are still in prison serving sentences for outdated law.
Is there any legal recourse for those who were convicted before marijuana possession became legal?
Ex Post Facto Laws Are Prohibited
Under Article I, Section 9 of the U.S. Constitution, ex post facto laws are prohibited.
An ex post facto law is "a law that retroactively alters a defendant's rights especially by criminalizing and imposing punishment for an act that was not criminal or punishable at the time it was committed, but increasing the severity of a crime ... by increasing the punishment for a crime ... or by taking away from the protections afforded the defendant." So, laws cannot be applied retroactively to convict you of a crime that wasn't a crime when you committed it.
Retroactive Amelioration Relief
Similarly, a new law decriminalizing a crime cannot be used to decrease or end a conviction that occurred prior to the new law's passage, unless the law has a retroactive amelioration clause.
For example, California passed Proposition 36 to amend the three strikes law to impose life sentence only when a third felony conviction is serious or violent. Before the amendment, many were sentenced to life in prison for non-violent crimes. The change wouldn't lessen their sentence. However, Proposition 36 also allowed courts to re-sentence offenders currently serving life sentences for non-violent third strike convictions. Proposition 36 allowed for retroactive ameliorative relief.
Applying for a Pardon
Unlike California's Proposition 36, Colorado and Washington laws decriminalizing and legalizing marijuana possession do not have any retroactive amelioration clauses.
Instead, current convicts may be able to get relief by applying for a pardon from their state's governor. Applying for and receiving a pardon is a very hard process and a rare success.
If you need help applying for a pardon, consult with an experienced criminal defense attorney.