Court rules teen will have to stand trial as an adult for murder of another teen at the Jackson Square T stop

If Ronaldo Cepeda wants to appeal his indictment on second-degree murder charges for the stabbing death of Mason Raymond in 2015, he'll have to wait until after his trial, if he's found guilty, the Supreme Judicial Court ruled today.

Cepeda, 16 at the time, is charged with fatally stabbing Raymond at the Jackson Square Orange Line stop on Oct. 22, 2015, allegedly after the two got into an argument that escalated into a fistfight that ended when Cepeda plunged a knife into Raymond's heart.

In his appeal, originally to a single SJC justice, Cepeda's lawyer argued prosecutors never gave the grand jury a detailed rundown of juvenile brain development, as an explanation for why there might be mitigating circumstances for the stabbing. This reduced the odds that the grand jury would have brought a lesser charge of manslaughter, which would have put Cepeda in juvenile court - where penalties are far reduced and the goal is rehabilitation, not punishment. If convicted of second-degree murder, Cepeda would face a mandatory sentence of life in prison with a chance of parole after 15 years.

In its ruling, the state's highest court said that the single SJC justice was within his rights to reject the appeal and that the time to appeal an indictment to a full appeals court is after the completion of a trial based on that indictment, not before.