Roxbury teen pleads guilty in 2023 double stabbing, sentenced up to 14 years in prison
BOSTON, June 4, 2025 – A Roxbury teen will serve up to 14 years in state prison after being sentenced today in a 2023 double stabbing that left a 21-year-old Roxbury woman dead and a Jamaica Plain teen with serious injuries, Suffolk District Attorney Kevin Hayden announced.
WILMARY MEJIA MATOS, 18, pleaded guilty to manslaughter for the fatal stabbing of Brianna Brown, 21, and assault and battery with a dangerous weapon causing serious bodily injury for the non-fatal stabbing of a 17-year-old on February 11, 2023.
Judge Mary Ames sentenced Mejia Matos to 10-14 years in prison followed by three years of probation.
On February 11, Mejia Matos, then 16, learned that her boyfriend had videotaped them having sex and sent the video to the 17-year-old victim. Mejia Matos believed the 17-year-old victim posted the video online. Mejia Matos confronted the victim over social media and the pair exchanged threats. The feud escalated to challenging one another to a fight, with the teenage girls planning to meet in Jamaica Plain.
Mejia Matos came with two male friends, one of whom tried to dissuade her from the altercation. The juvenile came with her brother and her brother’s girlfriend, Brown. Leading up to the incident, Mejia Mato sent the victims threatening voice texts and shared her location so the victims could see that she was on her way.
The fight was partially captured on video. Brown was stabbed 16 times, and the second victim was stabbed four times. Both victims made their way to a nearby police station to seek help, and both were transported to a local hospital, where Brown succumbed to her injuries.
Mejia Matos was also transported to the hospital and treated for an abrasion to her forehead and cuts on both her hands and wrists.
Both victims’ family members attended the sentencing and delivered victim impact statements, including one of Brown’s brothers, who spoke of her life, referring to it as “that of a dandelion, beautiful and fleeting. Here one day, gone the next.” He also shared insights into Brown’s character, ending with a message to Mejia Matos: “If I learned one thing from my sister, it’s how to forgive. I forgive you.”
Hayden said the brother’s statement demonstrated “amazing grace amid 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.
Assistant District Attorney Nathan McGregor prosecuted the case. Alexa Leduc is the assigned victim witness advocate.
All charged individuals are presumed innocent until and unless proven guilty beyond a reasonable doubt.
Suffolk County District Attorney Kevin Hayden’s office serves the communities of Boston, Chelsea, Revere, and Winthrop, Mass. The office handles over 20,000 cases a year. More than 160 attorneys in the office practice in nine district and municipal courts, Suffolk Superior Court, the Massachusetts Appeals Court, the Supreme Judicial Court, and the Boston Juvenile Courts. The office employs some 300 people and offers a wide range of services and programs to serve anyone who comes in contact with the criminal justice system. This office is committed to educating the public about the services we provide, our commitment to crime prevention, and our dedication to keeping the residents of Suffolk County safe.
James Borghesani, Chief of Communications