Criminal justice reform advocates in the Legislature want to give prisoners sentenced to life without parole a chance at freedom.

"Just sentencing people to die is not the way to make our Commonwealth safer and to bring justice to our many families," said Roxbury lawmaker Rep. Liz Miranda, whose own brother was killed, at an online event Thursday in support of the proposed legislation.

The bill, which is backed by the Legislature's Criminal Justice Reform Caucus, would allow for parole after 25 years in prison. According to Prisoners Legal Services of Massachusetts, more than 10% of those incarcerated in Massachusetts are serving life sentences without the chance for parole.

Rep. Jay Livingstone, a member of the caucus, says denying a convict any chance of freedom prevents rehabilitation and wastes public dollars on keeping an aging prisoner behind bars long after they've ceased being a public safety threat.

"It's not a get out of jail free card. It is the ability to prove, where an individual who's incarcerated decades after they commit a crime, to prove that they are not a threat to society, that they can be returned to society and be a productive member and comply with all the conditions of parole," said Livingstone, who is sponsoring the bill.

The families of several murder victims told lawmakers at a hearing earlier this month that allowing convicted murderers out of prison wouldn't bring justice for victims.

Opposed to the bill was Tom Ritzer, whose 24-year-old daughter Colleen, a Danvers high school math teacher, was killed in 2013 by her student Philip Chism.

"There's no justice strong enough for someone who rapes and murders your daughter," Ritzer said, according to the State House News Service. Chism is serving a life sentence but is eligible for parole in 40 years.

The legislation, if passed, would apply retroactively to prisoners who have already served 25 years.