The incident happened at about 2 a.m. along the 20000 block of Stephanie Drive near Charter Oak.
Investigators said the party was a small gathering of about 20 to 25 teens who were all invited guests. The homeowners were not home at the time, and the partygoers were in the backyard of the residence when a verbal argument began.
The subject of the argument was not known, but it escalated to a physical brawl. The victim, a 19-year-old man, was stabbed in the upper torso. He was transported to an area hospital where he was pronounced dead. His name was not immediately released.
Witnesses said the suspect flee the scene on foot.
Sheriff's deputies do not believe the stabbing was gang related. No arrests were made, but investigators said they knew who they were looking for and did not release a suspect description.
