Doing time for a crime that isn't a crime anymore might sound unfair.

But when local governments legalize the use, cultivation, and sale of recreational marijuana, people who were locked up for nonviolent pot crimes under the old law typically remain behind bars.

That's been the case in states such as Colorado, Oregon, Washington, and Alaska, and in Washington, D.C., as well.

With marijuana-related measures on the ballot this year in 14 states, including California, experts expect more of the same.

The U.S. is one of the few countries in the world where "retroactive ameliorative relief" in sentencing is not a given. That means if a new law abolishes or softens punishment for a crime, people convicted before the new law passes aren't guaranteed that their sentences will be relaxed or canceled. That means death row inmates aren't automatically let off the hook when a state abolishes the death penalty, for example.

In the case of new pot laws, additional legislation would have to be enacted to retroactively change a sentence.

“The courts don’t get to simply decide on their own what's fair or unfair,” Eric E. Sterling, executive director of the Criminal Justice Policy Foundation, told ATTN:. “If the law has not given them authority to reconsider such sentences, then it's unfair. But it's not illegal for the court to say, 'Sorry, there isn’t a basis for us to fix your problem.'”

Governors in most states have a power known as executive clemency that allows them, at their own discretion, to commute a person's sentence. But in Washington — which legalized certain amounts of pot possession in 2012, and in Oregon and Alaska, which both approved similar measures in 2014 — the governors haven't exercised that power for any marijuana convicts yet, officials said. The governor's office in Colorado said the same.

Authorities in the District of Columbia didn't respond to ATTN: inquiries about clemency granted to pot offenders or how many people might be incarcerated for pot possession. Officials in Colorado didn't immediately respond to requests for information about if any state prisoners were behind bards for pot possession.

The good news is that there are likely very few people doing hard time for possession of pot.

Oregon had about 30 people locked up for marijuana possession in September 2014, a couple months before the state legalized marijuana, according to data from the Oregon Department of Corrections. 

But marijuana possession is usually a misdemeanor, unless their are other circumstances contributing to someone's punishment, Sterling said. Most people would likely serve their time in jail rather than prison, and those sentences would rarely last longer than a month or so, unless other offenses or violent crimes were factored into the sentence, Sterling said. In Alaska, there isn't a single person in state prison simply for possession of marijuana, according to the Alaska Department of Corrections.

In the state of Washington, "according to our staff, as a preliminary matter, we don’t think there’s a single person currently in our prison system for marijuana possession," Tara Lee, deputy communications director for Gov. Jay Inslee, said in an email to ATTN:. "At least not for marijuana possession alone. It’s been de-emphasized by prosecutors for such a long time and has pretty light punishment associated [with it] that it’s almost always a misdemeanor."

While the number of people locked up for marijuana possession alone is relatively small, tens of thousands of people in states where pot is now legal still have arrests and convictions marring their records.

That means a person could still get disqualified from a job, have a hard time securing housing, be denied a loan, or suffer other fallout of having a criminal record, which is known as "collateral consequences."

"A policy of retroactive clemency could also help right some racial wrongs," Matt Ferner wrote for The Huffington Post:

The Marijuana Arrest Research Project report, which was based on FBI Uniform Crime Report data, found that in Colorado, Latinos have been arrested for marijuana possession at a rate 1.5 times that of whites. African-Americans have been arrested at a rate 3.1 times that of whites. Nationwide, Blacks are nearly four times more likely to be arrested for marijuana possession than whites, according to a report from the American Civil Liberties Union.

Why haven't advocates for legalizing recreational marijuana use taken into account people who are locked up under previous laws? Because they have had to be politically strategic, Sterling said.

“If you’re going to take a measure to the ballot box, the more complicated it is, the more different, the more varied things you include in it, the more opportunity your opponents have to try to poke holes in it,” he said. “And so the folks who designed these initiatives know a basic rule: Keep it simple.”

Colorado and Washington were the first two places to legalize recreational pot in the United States. State bills that would have helped clear people's records of misdemeanor marijuana convictions died in both states' legislatures.

A landmark 2014 ruling by the Colorado Court of Appeals offered hope that old marijuana convictions could be overturned. But the ruling's precedent likely only affected people whose pending appeal for post-conviction relief was filed before Colorado legalized recreational pot or those who still had a window of time to appeal in those pre-legalization cases, the Denver Post reported.

The only way someone's record can be cleared in Alaska is through a governor's pardon.

Last year, Oregon legalized recreational pot consumption. That was followed by policies that allowed some offenders to expunge marijuana offenses from their records. "Oregon is one of the first states to really grapple with the issue of what do you do with a record of something that used to be a crime and no longer is," American University law professor Jenny M. Roberts told The New York Times.

In 2014, the District of Columbia council legalized the possession, consumption, and cultivation of small amounts of marijuana. In October of that year, the council also approved a law that sealed the criminal records of residents who were previously convicted of low-level, nonviolent pot-related crimes. Councilman David Grosso sponsored the bill.

“For perspective, there were 20,000 arrests in the District of Columbia over a 10-year period for a nonviolent possession of marijuana," Grosso said in a statement released the month before his legislative victory. "This will help thousands of D.C. residents. The legislation is also critical to addressing barriers to employment, housing, and education."

If officials don’t put a period at the end of a criminal sentence — a measure to keep ex-offenders from suffering collateral consequences after they pay their debt to society — “it's a life sentence," Sterling told ATTN:.

“We are a land of second chances,” Sterling said. “In the U.S. Constitution, Congress is given the power to write bankruptcy laws. ... If you get into trouble and owe too much money, it’s a way you get a second chance economically. ... And the same kind of things should exist with respect to someone's personal conduct, that we recognize people — especially young people — make all types of immature mistakes, and that we as a society cannot prosper if everybody who makes a mistake gets excluded from earning a living.”