An 18-year-old has been sentenced for a deadly 2023 stabbing in Boston’s Jamaica Plain neighborhood that prosecutors say was the result of a feud started when the suspect’s boyfriend sent an explicit video to one of the victims.

Wilmary Mejia Matos, of Roxbury, pleaded guilty to manslaughter in the death of Brianna Brown, 21, and to assault and battery with a dangerous woman causing serious bodily injury for the stabbing of a 17-year-old on February 11, 2023, according to the Suffolk County District Attorney’s Office.
According to prosecutors, Mejia Matos had learned that her boyfriend had sent a video of the couple having sex to the 17-year-old victim. Mejia Matos confronted the 17-year-old, believing the victim had then shared the video online. The feud escalated when the two exchanged threats on social media and they challenged each other to a fight, planning to meet in Jamaica Plain.
Mejia Matos came with two friends, one of whom was trying to stop her from fighting. The 17-year-old came with her brother and brother’s girlfriend, Brown. The group met up on Woodside Avenue. During the fight, Brown was stabbed 16 times and the 17-year-old was stabbed four times. Brown died of her injuries at the hospital.
During sentencing, family members of both victims spoke, including Brown’s brother, who described her life like “that of a dandelion, beautiful and fleeting.”
“If I learned one thing from my sister, it’s how to forgive. I forgive you,” he said.
Suffolk County District Attorney Kevin Hayden commended the brother for “amazing grace under unfathomable grief.
““Everything about this case is tragic: The loss of one young woman, the serious injury of another and the conviction and incarceration of a third. The combined elements of youth, impulsiveness and social media weaponization forged an incident that ended one life and forever altered many others. It’s the saddest of situations for all involved, and a sad situation for the city itself,” Hayden said in a media release.
Mejia Matos was sentenced to 14 years in state prison.