Nyasani Watt was 10 days shy of his 18th birthday when he fatally shot another teenager and wounded his friend on a Dorchester street in 2011, with a gun that had been handed to him by Sheldon Mattis, who was already 18.
Both of them were convicted of first-degree murder for killing 16-year-old Jaivon Blake and sentenced to life in prison. But only Watt will get a chance to argue for parole some day because mandatory life sentences are banned for juvenile killers, based on a Supreme Court finding that teenage brains are still developing.
The state Supreme Judicial Court upheld the convictions of Watt and Mattis in April, but raised concerns about the constitutionality of the disparate sentences. It ordered the trial judge to hold hearings on evolving research on brain development to help the court determine whether the ban on mandatory life sentences should be extended to young adults.
The case, part of a growing challenge to sentences of life without parole for young adults, sparked a heated legal clash between Suffolk District Attorney Rachael Rollins and four district attorneys who sought to intervene in the matter to argue against raising the age limit.
On Thursday, a day after the high court rejected the prosecutors’ bid, Rollins dismissed the effort to intervene as “nothing more than a misogynistic wolf in sheep’s clothing” and said she did not need her colleagues’ input to address the issue of whether an 18-year-old’s brain is cognitively different than an older adult.
“For the four men to imply that my experienced and able team of Assistant District Attorneys can’t handle an evidentiary hearing is outrageous,‘' Rollins said in a statement. “We look forward to conducting the evidentiary hearing on the development of the brains of emerging adults.”
In court papers, Norfolk District Attorney Michael Morrissey, Plymouth County District Attorney Timothy J. Cruz, Essex District Attorney Jonathan Blodgett, and Cape and Islands District Attorney Michael O’Keefe said there are 92 inmates from their counties who are serving mandatory life sentences for murders they committed between the ages of 18 to 22. meaning they would be eligible for parole hearings if the court changes the rules.
“This is an issue which will have statewide implications for families of murder victims. We sought to have a voice at the trial level where the record upon which the SJC will ultimately rule will be created,‘' O’Keefe wrote in an e-mail. “Yes, we will be filing an amicus curiae brief at that time but that’s a little like closing the barn door after the horse has escaped.”
In her court filing, Rollins said there was no precedent for other district attorneys to intervene.
“Never has this Court allowed one (let alone four) elected district attorneys to intervene in another district attorney’s matter,” she said in her court filing. “That long-standing record should be left intact. The motion should be denied on the papers.”
O’Keefe criticized Rollins for her reaction to his legal stance.
“These are policy differences but it’s become increasingly clear that if you don’t agree with District Attorney Rollins you are called a racist or a misogynist or both,‘' he wrote. “Citizens can read the various filings for themselves and make up their minds as many Globe readers already have based on the published comments.”
The four prosecutors, two Democrats and two Republicans, wrote in court papers that they disagreed with the position Rollins appears to be taking. And they argued they need to be in the courtroom and have the ability to call their own witnesses to counter those called by Rollins or the defense.
The dispute comes amid a broad reassessment of how young offenders, even murderers, should be prosecuted and punished, and whether bans on mandatory sentences of life without parole for juveniles should extend into adulthood, across the traditionally bright-line divide of age 18.
“States are saying, ‘Why would we stop at 18?’ ” said Joshua Rovner, a senior advocacy associate at The Sentencing Project Campaign to End Life Imprisonment. “Everything we know about brain development says nothing really magical happens at 18.”
Since the US Supreme Court ruling, 23 states and Washington, D.C. have banned life sentences without parole for juveniles, Rovner said.
In Massachusetts, juvenile justice advocates, academics, and even some prosecutors have been pushing for legislation that would give young adults who are convicted of murder a chance at parole, a campaign that has met sharp resistance from victims’ families and many law enforcement officials.
At the same time, courts are weighing a number of legal challenges from inmates convicted of murder as young adults, arguing that concerns about the culpability of juveniles due to their still-evolving brains should also apply to an older group known as “emerging adults.”
The idea of giving young adult murderers a second chance stands in sharp contrast to the punitive philosophy of the 1990s, when Massachusetts required that anyone 14 or older who is charged with murder be tried as adults.
That law still stands, but the legal landscape has shifted significantly. In 2012, the Supreme Court ruled that mandatory life without parole sentences are unconstitutional for juveniles because they fail to consider their underdeveloped sense of responsibility, which can lead to impulsiveness and recklessness, or their greater “capacity for change.”
The next year, the SJC went a step further, banning life without parole sentences for juveniles and applying it retroactively, giving dozens of young killers a chance at freedom after serving 15 years in prison. Since then, 49 of 65 inmates impacted by the ruling have asked the parole board to be released, according to the state’s Executive Office of Public Safety and Security. Nineteen have been granted parole; 30 have been denied.
On Thursday, Norfolk District Attorney Michael Morrissey said the motion to intervene “was so that we would be able to submit scientific evidence for the court to consider, which cannot be accomplished by filing an amicus brief.”
“This is not personal, and it is not specific to Suffolk County or the facts of the underlying case. The SJC has set this as a test case that may change precedent statewide,‘' he said.
Berkshire District Attorney Andrea Harrington and Northwest District Attorney David Sullivan filed a letter with the SJC supporting the defense’s claim that life sentences without parole for those who commit murder when they are 18, 19, or 20 are unconstitutional.
O’Keefe also issued a joint statement with Cruz and Blodgett on Thursday, noting that the SJC barred life sentences for juveniles convicted of first degree murder in 2014 based on the court’s view that the brain of someone under the age of 18 is not the same as a chronological adult.
“We hold a differing view on a complex and difficult issue of criminal justice policy,” the three district attorneys said in the statement. “DA Rollins staked out a position that such [life without parole] sentences for so called ‘emerging adults’ 18-22 are unjust and that she supports redrawing that line a mere six years later.”
In 2014, the state adopted a parole system that requires juvenile killers convicted of first-degree murder after that date to serve between 20 and 35 years before they are eligible for parole.
In the Mattis case, his lawyer, Ruth Greenberg, has argued that basing his sentence on a bright-line “birthday rule” was unconstitutional.
“All the adolescent brain science compelling the constitutional mandate making Watt parole eligible after 15 years apply equally to Mattis, just eight months older,” Mattis’s attorneys wrote in a brief. “He is equally capable of redemption.”