Mastic, New York — A violent confrontation on Long Island has led to the arrest of two teenage sisters after a young man was brutally stabbed while protecting his younger sibling, authorities said.
Confrontation Outside Suffolk County Home Turns Violent
The incident occurred around 10:20 p.m. Saturday outside a residence in Mastic, according to Suffolk County Police.
The victim, identified by family as 21-year-old Nico Cassetana, allegedly stepped in when two sisters — Diamond King, 18, and Myia King-Harrison, 19, both from Bay Shore — became aggressive toward his 14-year-old sister.
What began as a heated argument escalated into a violent stabbing, leaving Cassetana gravely injured.
Victim Hospitalized in Critical Condition
Cassetana was rushed to Stony Brook University Hospital, where he was later placed into a medically induced coma, his father Lionel Cassetana told local media.
The Post reported that the wounded victim called 911, alerting dispatchers that he had just been stabbed while trying to protect his younger sister.
Police say the stabbing left him with severe injuries that required immediate surgical intervention.
Father Says Son Acted to Save His Sister
Speaking to reporters, Lionel Cassetana described his son’s actions as instinctive, calling him a protective older brother who stepped in under dangerous circumstances.
“It’s a normal thing to do,” the father said. “I’m glad my son was there and he survived because my daughter would’ve gotten stabbed.”
He added that his daughter, though tall, is very slim, and fears she may not have survived a stabbing.
The father also told News 12 that his daughter has been targeted previously by a group of girls — raising concerns that this incident may have been part of an ongoing pattern of harassment.
Sisters Face Serious Charges
Police confirmed that Diamond King and Myia King-Harrison were taken into custody on Sunday.
Both have been charged with:
- First-degree gang assault
- First-degree assault
The sisters are expected to be arraigned Monday in Suffolk County Court.
Authorities have not yet released a suspected motive beyond the dispute involving the younger sibling.
Community Shock and Ongoing Investigation
Neighbors expressed alarm at the violent nature of the confrontation, saying it is frightening to see teenagers involved in such aggressive behavior.
Police are continuing to investigate, including whether others were involved or if the stabbing was premeditated. Detectives are also reviewing additional video evidence and speaking with witnesses who were present at the scene.
Family members say the victim’s younger sister has been entangled in previous altercations involving a group of local teenagers. Her father fears retaliation may continue if the situation is not handled seriously by authorities.
Meanwhile, the family remains at the hospital as Cassetana fights for recovery. Loved ones say they are hopeful but preparing for a long medical journey.
How do you think communities should handle escalating teen violence? Share your thoughts in the comments.
