16-year-old girl ordered held without bail on murder charge in fatal Jamaica Plain stabbing

Defense attorney Stephen Weymouth spoke to the media outside West Roxbury Municipal Court Monday.Pat Greenhouse/Globe Staff

A 16-year-old girl was ordered held without bail on a murder charge Monday, two days after she allegedly stabbed a 21-year-old woman to death and wounded a 17-year-old girl in an apparent dispute over an explicit photo, officials said.

At her arraignment in West Roxbury Municipal Court, Wilmary Mejia Matos pleaded not guilty to charges of murder and assault and battery with a dangerous weapon. Her next court date is slated for March 24.

Mejia Matos is accused of fatally stabbing Brianna Brown, 21, and attacking the 17-year-old, who was not identified.

Police received a 911 call about the stabbing around 5 p.m. Saturday. As officers rushed to Woodside Avenue in Jamaica Plain, the two victims ran inside a police station just 300 feet away from where the attack occurred, police said.

The victims were taken to Boston hospitals but Brown did not survive, police said. The 17-year-old was seriously injured but is expected to live, police said.

In court Monday, Assistant District Attorney Nathan McGregor said it appeared that Mejia Matos’s boyfriend had sent “some explicit photos” to the two victims.

Mejia Matos took a bus from her mother’s house in Dorchester to Jamaica Plain and brought two male friends with her, McGregor said. They both tried to dissuade her from carrying out the attack, he said.

”The defendant sought to fight one or both of the victims,” McGregor said. “She went there with the explicit purpose to harm the victims.”

Both victims were stabbed in the neck, McGregor said. Brown was also stabbed in the chest, he said.

Mejia Matos and her boyfriend ran from police and hid, McGregor said. When officers caught up to her, they found a knife near her, he said.

Mejia Matos suffered cuts to her hands “consistent with a person wielding a knife and not knowing how to use it,” McGregor said.

Her lawyer, Stephen Weymouth, told reporters outside the courthouse that Mejia Matos was “extremely remorseful.”

“She’s 16 years old,” he said. “I thought maybe a more appropriate initial charge would have been manslaughter, which would have been handled initially in the juvenile court, not the district court.”

“I’m suggesting that there are issues like self-defense,” Weymouth added. “Sudden provocation, heat of passion, they’re all aspects and issues that could rise to the level of obviating malice” and therefore make her not culpable for murder.

Suffolk District Attorney Kevin R. Hayden’s office said a juvenile between the ages of 14 and 17 who is charged with murder is arraigned as an adult.

“The scope of this tragedy is immense,” Hayden said in a statement. “One young woman is dead, another is seriously injured, and a third is entering a life-altering journey through the court system. The trauma of this incident touches all of them, and all of their families. It also touches anyone who hopes and prays for a community less beset by pain and loss.”

Weymouth said Mejia Matos’s mother and sister were in court Monday and questioned why she was being charged as an adult with murder.

“Maybe she wanted to go for a fight, but that’s not premeditated murder,” he said. “Some things could have happened when she got wherever she got that turned the whole situation around. And that’s, it’s a little early to tell. But there’s definitely issues here that need to be checked and need to be followed up.”

He said he wasn’t sure why Mejia Matos brought a knife to the encounter.

“Some people just carry knives around for protection,” Weymouth said.

Weymouth was asked about a possible romantic dispute among the parties.

“I guess that maybe could be part of the problem, maybe the reason for a fight or something like that,” Weymouth said. “But again, just because she went somewhere from point A to point B, maybe had a knife, did have a knife, but that doesn’t necessarily [indicate] premeditation for murder in my opinion.”

John R. Ellement of the Globe Staff contributed to this report.