On Wednesday, Wilmary Mejia Matos, 18, pleaded guilty to manslaughter and aggravated assault with a dangerous weapon following the stabbing death of Brianna Brown, a 17-year-old, and the wounding of Edlany Rosario, also 17.
Suffolk Superior Court Judge Mary K. Ames sentenced Mejia Matos to a prison term ranging from 10 to 14 years as part of a plea agreement with prosecutors.
Mejia Matos will receive credit for two years already served in pre-trial confinement.
Denzil Pierre, the brother of the victim, delivered a powerful statement in court, recalling his sister’s tragic death.
“[My sister] was murdered, not in self-defense, but out of malevolence, insecurity, and male validation,” Pierre stated emotionally.
He acknowledged that while Brianna was not perfect, she was still a human being with a future cut short in a brutal manner.
Pierre expressed his forgiveness towards Mejia Matos despite the circumstances, saying, “I have no hate in my heart, no malice, no grudge. I forgive you.”
During the emotional courtroom proceedings, Mejia Matos briefly locked eyes with Denzil but largely kept her head down while listening to witness testimonies, appearing visibly affected by the moments.
Brown’s mother, Carla Andrews, who wore a purple suit jacket adorned with a button featuring Brown’s image, remembered her daughter fondly as aspiring veterinarian with a love for animals.
“Bri would assist anyone who was being treated unfairly, maybe to her own detriment,” Andrews explained, highlighting that her daughter was a protector and advocate for the underdog.
Suffolk Assistant District Attorney Nathan McGregor outlined the tragic sequence of events leading to the fatal confrontation, noting that a feud over social media escalated into violence.
On February 11, 2023, Mejia Matos discovered her “on again, off again” boyfriend had been seeing Rosario, which led to jealousy and hostility.
Following the revelation, Mejia Matos found a
image source from：https://www.bostonglobe.com/2025/06/04/metro/boston-teen-pleads-guilty-manslaughter-deadly-attack-woman-after-social-media-feud/
