Teen Bullies Turn Violent: Gruesome Stabbing SHOCK

Stabbing,Attack.,Hand,With,A,Knife.,Murder,With,A,Knife.

Two teenage sisters from Long Island now face decades in prison after allegedly stabbing a 21-year-old man who was simply trying to protect his younger sister from their relentless bullying campaign.

Story Snapshot

Diamond King, 18, and Myia King-Harrison, 19, charged with first-degree gang assault for stabbing Nico Cassetana outside his Mastic home
Victim remains in medically induced coma after multiple surgeries, was defending his 14-year-old sister from ongoing bullying
Attack occurred Saturday night after escalating harassment campaign against the younger girl
Both suspects arrested within 24 hours and arraigned on serious felony charges that could result in lengthy prison sentences

When Protection Becomes Perilous

Nico Cassetana made a split-second decision that any protective older brother would make. When a group of girls showed up at his family’s Mastic home targeting his 14-year-old sister, he stepped outside to intervene. That decision nearly cost him his life. The two King sisters allegedly attacked him with a knife, leaving him fighting for survival in a hospital bed while they now face the possibility of spending their prime years behind bars.

The October 25 incident unfolded around 10:20 p.m. near Dana and Dean avenues, turning a quiet residential neighborhood into a crime scene. Suffolk County police responded swiftly, but the damage was already done. Cassetana lay bleeding from a stab wound to his back while the alleged attackers fled the scene.

2 Long Island sisters charged with gang assault after allegedly stabbing 21-year-old man — who was defending his younger sister https://t.co/wFs54MiQm6 pic.twitter.com/l43fmQRMOp

— New York Post (@nypost) October 27, 2025

A Pattern of Escalating Harassment

This wasn’t a random act of violence but the culmination of an ongoing campaign of harassment. According to Cassetana’s father, Lionel, his daughter had been repeatedly targeted and bullied by a group that included the King sisters. The younger Cassetana had become the focus of their attention for reasons that remain unclear, even to investigating officers.

What started as a typical teenage drama spiraled into something far more sinister. The bullying escalated until it reached the family’s doorstep, forcing Nico to make a choice between his safety and his sister’s wellbeing. He chose a family, and it nearly killed him. The surveillance cameras that captured the attack now serve as crucial evidence in a case that highlights how quickly peer conflicts can turn deadly.

Justice Swift but Recovery Uncertain

Within 24 hours of the stabbing, Suffolk County police had both sisters in custody. Diamond King and Myia King-Harrison were arraigned at First District Court in Central Islip on charges of first-degree gang assault and first-degree assault. The “gang assault” designation reflects the coordinated nature of their attack and significantly increases the potential penalties they face.

While the legal system moves forward with prosecuting the alleged attackers, Nico’s recovery remains uncertain. Multiple surgeries have stabilized his condition, but doctors keep him in a medically induced coma at Stony Brook University Hospital. His family maintains a bedside vigil, grateful he survived but uncertain about his long-term prognosis. The young man who stepped up to protect his sister now depends on machines to sustain his life.

Community Grapples with Youth Violence Reality

The Mastic community now confronts an uncomfortable truth about youth violence in their neighborhood. This wasn’t gang warfare or drug-related crime, but teenage girls allegedly attempting to seriously harm someone over interpersonal drama. The incident forces parents and community leaders to examine how bullying prevention efforts have failed and what signs they might have missed.

The King sisters, barely out of high school themselves, now face adult consequences for their alleged actions. If convicted on the most serious charges, they could spend significant portions of their adult lives incarcerated. Their decision to allegedly escalate a bullying situation into attempted murder has destroyed multiple families and shattered any illusions about teenage conflicts being harmless drama. The investigation continues as the community struggles to understand how neighborhood tensions exploded into life-threatening violence.