It happened at a house party on Morgans Avenue near Avenue 278 in Exeter just before one on Saturday morning.
Deputies say they found two shooting victims - a 15-year-old and a 23-year-old man.
Fifteen-year-old Jessie Ambriz was pronounced dead at the scene.
The 23-year-old was transported to a local hospital with non-life-threatening injuries.
The person hosting the gathering was not there when deputies arrived - that's one of the many people they're still hoping to speak with.
There were both teenagers and adults at this party. Only about 10 people stayed behind to speak with detectives.
Neighbors say the party got pretty loud around midnight.
Sheriff's deputies rushed to the neighborhood an hour later after an argument escalated and someone pulled out a gun.
We know neither of the shooting victims lived at the house where the shooting happened.
The sheriff's office says there's still a lot of evidence to gather and witnesses to talk to.
"We know there are people out there that know what happened and are likely witness to it. We'd like them to come forward and talk to us. They can remain anonymous," said Lt. Jason Kennedy.
Deputies also believe there was only one shooter - they need the public's help finding that person.
Anyone with information is asked to call the Tulare County Sheriff's Office.