When Calvin McNeill was 16, he and a group of friends in Baltimore decided to rob a neighborhood dice game. Things got chaotic, and McNeill shot and killed a man. It was 1981. The teen was sentenced to life in prison.

Over the next 39 years, McNeill became a model inmate and was approved for parole three times, but each time the Maryland governor vetoed his release. So Baltimore State’s Attorney Marilyn Mosby joined a defense motion to reconsider his sentence last summer. A judge granted it, and McNeill was freed in July this year.

Since his release, “everybody that I have come across has opened up their arms to me,” McNeill said, “and said, ‘We’re glad to see you home. And we understand that you were a baby when you got locked up.’”

On Monday, Mosby announced the launch of a sentencing review unit in Baltimore to address both mass incarceration and racial inequities in the justice system. Of the 2,500 people serving life sentences in Maryland, 79 percent are Black, Mosby said, though African Americans make up only 30 percent of the state population. In Baltimore, of the 815 prisoners sentenced to life, 94 percent are Black.

Also Monday, the newly elected district attorney of Los Angeles, George Gascón, announced at his swearing-in that he, too, is launching a sentencing review unit. Gascón said he conservatively estimates that 20,000 prisoners will immediately qualify for resentencing. He said he believes some were given drastically long sentences, others are older and unlikely to reoffend, and others should be released because of covid-19 concerns.

“The role of a prosecutor is not only one of seeking justice,” Gascón said in an interview, “but also of correcting injustice . . . This is going to be the first time in the nation where there will be this massive effort coming from the largest prosecution offices in the country.” He said half of Los Angeles’s prisoners are rated low-risk to reoffend and if thousands are released, “there will be billions of dollars in savings” on incarceration costs.

“This is gigantic,” Gascón said.

The push to begin revisiting lengthy prison sentences, as part of the justice reform effort being promoted by big city prosecutors around the country, is gaining momentum even in states like Maryland, where there is no formal mechanism for prosecutors to revisit settled cases. Prosecutors in San Francisco, Boston, Philadelphia and Brooklyn are also launching sentencing review initiatives.

While a growing number of prosecutors also are seeking to uncover and reverse wrongful convictions, which occur in a small percentage of cases, the move to release those who were correctly convicted but have now served decades in prison could have a far wider impact. More than 2 million Americans are in jail or prison, which is believed to be the highest incarceration rate in the world.

In Washington state, a bill allowing prosecutors to seek resentencing passed this year, and the district attorney in Seattle announced a sentencing review unit in June. But the office had already been quietly achieving prisoner releases since 2007, “with a bit of a wink to the judge,” King County District Attorney Dan Satterberg said. “We knew no one was going to appeal it.”

In the District, the city has released 53 inmates since passing a law in 2016 allowing for resentencing if the offender was younger than 18 and served at least 15 years in prison. Now the city council is considering expanding the group of eligible inmates to those who committed crimes at age 24 or younger and have spent 15 years incarcerated.

Last year in Prince George’s County, newly elected State’s Attorney Aisha Braveboy created the state’s first conviction and sentencing integrity unit to review both convictions and sentencings that might deserve new consideration. Seven people sentenced to life as juveniles have been released, an office spokeswoman said.

Extreme sentences, particularly those that wouldn’t be imposed today, divert resources away from the root sources of crime, turn prisons into elder care centers and alienate communities torn by mass incarceration, said Miriam Krinsky, executive director of Fair and Just Prosecution, which helps organize and coordinate newly elected prosecutors.

“When the system is out of alignment with communities,” Krinsky said, “people will stop trusting the system and stop cooperating, and then we’re all at risk.”

Prosecutors launching such efforts have devised a number of factors to consider for each case, such as the prisoner’s original crime, their rehabilitation in prison, their plan for reentry into society, their likelihood to reoffend and the opinions of the victims in their case. A number of experts said that victims often don’t oppose the release of the offender and that the occurrence of new crimes by those released is low.

Aswad Thomas, the managing director of Crime Survivors for Safety and Justice, was shot twice and nearly died in a robbery in 2009. He said that victims are often left out of justice reform discussions and that “victims are advocating for less focus on punishment and more on mental health treatment and drug treatment.”

Thomas and others noted a large percentage of criminals — the National Center for Victims of Crime estimated 90 percent — were crime victims themselves. “Crime survivors want these individuals [who may be released] being able to access jobs, housing and support without the barriers they face,” Thomas said. “I think it’s important for survivors to be at the table to remove those barriers.”

Thomas cited studies that showed recidivism was rare among people who had served lengthy sentences. Only about 1 percent of juvenile offenders released after receiving life sentences in Philadelphia reoffended; those released in Maryland after serving 30 years had a 2 percent recidivism rate; those who are released at age 50 or older have a recidivism rate between zero and 2 percent.

“Victims really prefer prison reform that’s done meaningfully and safely,” Renée Williams of the National Center for Victims of Crime said, “rather than keeping individuals in prison longer.” She said victims want to be heard and notified of releases but that “60 percent of victims would prefer prison spending be focused on rehabilitation over long sentences.”

In Seattle, Satterberg said he knew about long sentences. He became an assistant prosecutor in 1985, and “I was there when we were racking people up for life sentences, who were very young. I didn’t really think twice about it.” Young men doing armed robberies during the crack epidemic of the 1980s were receiving life sentences without parole, which Satterberg came to realize was disproportionate.

When Satterberg became chief prosecutor in 2007, his office began supporting defense motions for clemency in such cases, and 30 prisoners have been released. He said the original sentencing judges often supported the releases and said they were required to issue long terms by overly punitive laws such as “Three Strikes,” meaning three convictions required a life sentence. Satterberg said he rarely seeks a “Three Strikes” sentence now.

“Our willingness to look backwards has bought us a lot of good will in the communities,” Satterberg said. He said those who’ve been released often work with young people or serve as violence interrupters, that “they’re credible and they’re visible.”

In Baltimore, both Mosby and the woman she hired to launch her sentencing review unit, former deputy state public defender Becky Feldman, experienced crime first hand. Mosby’s cousin was shot and killed outside her house in Boston when Mosby was 14. Feldman’s brother was killed in Baltimore when she was 23.

Both said the experiences they had with the justice system, with prosecutors and victim advocates, inspired them to become criminal lawyers. Mosby said she has greatly ramped up victim services in her office, and her personal experience “spawned my passion to reform the criminal justice system.”

Feldman and others emphasized that those who seek release will only be guaranteed a review, not necessarily a release. Maryland is one of only three states, along with California and Oklahoma, that require the governor’s approval for parole, and a bill to allow Maryland inmates to seek release after a lengthy incarceration, the Second Look Act, is still pending.

Mosby and Gascón said in interviews that their new units would reconsider sentences that wouldn’t be handed down today, and both said reducing the number of prisoners possibly exposed to the coronavirus would help not only the prisoners but the surrounding communities who staff the prisons. Baltimore will review those 60 and over who have served 25 years, or those sentenced as juveniles who have served 25 years, Mosby said.

Gascón was a police officer and commander in Los Angeles before becoming a prosecutor. He knows he will be criticized for not being “tough on crime” but said, “I actually think this is a better path to protecting public safety.”

Sonia Kumar, a lawyer with the American Civil Liberties Union of Maryland, represented McNeill for years. She said many long sentences were handed down with the understanding that defendants would be released someday, before parole became a political consideration. “We wrongly teach victims,” Kumar said, “to measure justice through the length of time somebody serves in prison.”

And so she pushed for McNeill’s release and his approval for parole, only to see it rejected last year by Gov. Larry Hogan (R). Then she convinced Mosby’s office to join her motion for a sentence modification, which Baltimore Circuit Court Judge Pamela J. White granted in July, saying his rehabilitation, remorse and sense of responsibility warranted it.

“I never gave up hope,” McNeill said. He said that when he was 16, “I thought I knew everything. As you grow, you realize you did a lot of silly, crazy things.” He repeatedly expressed his regrets to the family of Rodney Young, whom he killed in 1981.

He works at a job lined up by his brother in a storage and moving company. He said he wants to start speaking with teens. “I want to tell them what I went through,” McNeill said. “If you don’t stay straight, you end up either in prison or a graveyard.”