Cases challenge no-parole terms for young adult killers

BOSTON (AP) — They were convicted of the same crime: the 2011 killing of a Boston teen as part of a gang feud. But Nyasani Watt — who pulled the trigger — will be able to fight for his release on parole after 15 years because he was only 17 at the time of the killing.

Sheldon Mattis, who was just eight months older, was ordered to spend the rest of his life behind bars.

U.S. Supreme Court rulings and state laws in recent years have limited or banned the use of life sentences without the possibility of parole for people who commit crimes as juveniles because of the potential for change.

Now, research showing that the brain continues to develop after 18 is prompting some states to examine whether to extend such protections to young adults like Mattis, who say they too deserve a second chance.

“People who say that a person of 18 and six weeks is biologically different than a person of 17 and 364 days belong to the Flat Earth Society,” said Mattis' attorney, Ruth Greenberg. “There is no support for a bright-line rule at 18, biologically, neuro-scientifically speaking. And the scientific community is in broad agreement,” she said.

Mattis' case and another, involving a man convicted of participating in a killing at 19, hope to ban life-without-parole sentences for people who were 18, 19 and 20 at the time of their crimes. The two cases were recently sent up to Massachusetts' highest court, which did away with such sentences for juveniles eight years ago.

The U.S. Supreme Court in 2012 struck down automatic life terms with no chance of parole for killers under 18. But this year, the more conservative court made it easier to hand down those punishments for juveniles, ruling that it doesn’t require a finding that a minor is incapable of being rehabilitated.

Despite that case,...