A New York teenager will spend his young adulthood behind bars after he stabbed another teenager to death at a house party last year.

Aiden Zachary, 18, pleaded guilty to first-degree manslaughter in connection with the death of 15-year-old Liam Delemo.

Zachary was originally charged with second-degree murder after he was arrested for stabbing Liam at a house party in West Babylon, New York, on Nov. 3, 2025. Suffolk County police said that 90 to 100 people were at the house party, which was advertised on social media. Local NBC affiliate WNBC was in the courtroom when Zachary’s defense attorney, Jacob Kaplan, said his client showed up with a group of friends and they were asked to leave.

When Zachary and his friends turned to leave, Kaplan said, other partygoers were “throwing drinks and other stuff at them as they left,” which led to a fight.

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Kaplan said Zachary “did not start any physical altercation that night, but unfortunately, his actions caused Liam’s death.”

In a press release, Suffolk County District Attorney Ray Tierney said, “The defendant’s violent behavior will follow him, and affect the lives of multiple families, long after his sentence is served.”

Police said at the time of Zachary’s arrest that the party was thrown by another teenager. Tierney said Zachary and his friends arrived “without an invitation.” The fight that ended with Liam being stabbed “in the abdomen and arm” occurred around 10:30 p.m. Zachary fled the scene after the stabbing. Liam was taken to a nearby hospital, where he died during surgery.

Zachary was arrested a week after the stabbing. On Nov. 4, a year and a day after Liam’s death, Zachary was sentenced to 12 years in prison followed by five years of post-release supervision. He apologized in court, saying, “I wish I could take it back.”

More from Law&Crime: 17-year-old stabbed another teen to death at massive house party where 90 to 100 attended: Police

The homeowner, 71-year-old Bonnie Miranda, also faced charges in connection with the fatal stabbing. Miranda, the grandmother of the teenager who threw the party, was charged with breaking Suffolk County’s Social Host Law and endangering the welfare of a child. Law&Crime reached out to the district attorney’s office for more information about the charges against Miranda, but did not receive an immediate response.